Topic  Name  Description 

Course Introduction  Course Syllabus  
Course Textbook (Online)  Many resources in this course will reference this textbook. You can also access a PDF version of the textbook here. 

Course Textbook (PDF)  Many resources in this course will reference this textbook. You can also access an online version of the textbook here. 

Course Terms of Use  
Unit 1: The Basics of Geometry  Unit 1 Learning Outcomes  
1.1: Language and Notation of Basic Geometry  Khan Academy: "Language and Notation of Basic Geometry"  Take notes as you watch this video to learn about the language and notation of basic geometry including line, line segment, ray, midpoint, collinear, and planar. Watch the presentation carefully two or three times until you are able to explain how to understand the terminology and notation associated with these terms. 
Khan Academy: "Lines, Line Segments, and Rays"  Take notes as you watch this video to learn about how to identify the differences between a line, line segment, and a ray. Watch the presentation carefully two or three times until you are able to explain how to understand the differences with these terms. 

CK12: Victor Cifarelli's "Geometry: Points, Lines, and Planes"  Study the "Points, Lines, and Planes" section. This section provides examples and definitions of point, line, plane, space, segment rays, postulates, and draw diagrams. Then, complete questions 110. These questions will provide you with the opportunity to identify general geometry terms and draw diagrams. The solutions to these problems are located in the "Answers" section. 

Khan Academy: "Points, Lines, and Planes"  Complete this assessment, which tests your knowledge on basic geometry terminology. You can review the concepts associated with these questions with the Khan videos in subunit 1.1. Compute the answer to the given problem, and input your response into the answer box. Then, click on "Check Answer" to see if you were correct or if you need to try again. 

Khan Academy: "Identify Rays, Lines, & Line Segments"  Complete this assessment, which tests your knowledge on basic geometry terminology. You can review the concepts associated with these questions with the Khan videos in subunit 1.1. Compute the answer to the given problem, and input your response into the answer box. Then, click on "Check Answer" to see if you were correct or if you need to try again. 

1.2: Distance between Two Points  CK12: Victor Cifarelli's "Geometry: Distance between Two Points"  Take notes as you read this section and watch the embedded videos to learn about the distance between two points and the segment addition postulate. Watch the presentations carefully two or three times until you are able to explain how apply finding the distance between two points and the segment addition postulate. This section provides examples of measuring on a ruler and finding the distance between points. 
CK12: Victor Cifarelli's "Geometry: Distance between Two Points"  Select the "Practice" tab, and complete the activity on the distance between two points and the angle addition postulate. Compute the answer to the given problem, and select your response. Click on "Submit Answer" to see if you choose the correct or an incorrect answer. Then, click on "Next" to move on to another question. You have completed the activity when you see "You have reached the maximum practice questions." (Note: You can refresh the page if you would like additional practice problems and the questions will be different than the first set.) 

1.3: Midpoints and Segment Bisectors  CK12: Victor Cifarelli's "Geometry: Midpoints and Segment Bisectors"  Take notes as you read this section and watch the video to learn about midpoints and segment bisectors. This section provides examples of measuring on a ruler and finding the distance between points. 
CK12: Victor Cifarelli's "Geometry: Midpoints and Segment Bisectors"  Select the "Practice" tab, and complete the activity on the midpoints and segment bisectors. Compute the answer to the given problem, and select your response. Click on "Submit Answer" to see if you choose the correct or an incorrect answer. Then, click on "Next" to move on to another question. You have completed the activity when you see "You have reached the maximum practice questions." (Note: You can refresh the page if you would like additional practice problems and the questions will be different than the first set.) 

1.4.1: Angle Basics  Khan Academy: "Angle Basics"  Take notes as you watch this video to learn about the language and notation of angles. Watch the presentation carefully two or three times until you are able to explain how to understand the terminology and notation associated with these terms. 
1.4.2: Measuring Angles  Khan Academy: "Using a Protractor" and "Measuring Angles in Degrees"  Take notes as you watch these videos to learn about how to use a protractor and to measure angles in degrees. Watch the presentations carefully two or three times until you are able to measure an angle with a protractor and measuring angles in degrees. 
CK12: Victor Cifarelli's "Geometry: Angle Measurement"  Read this section, which provides examples of measuring with a protractor and understanding the angle addition postulate. 

CK12: Victor Cifarelli's "Geometry: Angle Measurement"  Scroll down to the "Review" section, and complete exercises 117. These exercises will provide you with the opportunity to use the angle addition postulate, properties of angles, and draw and measure . 

1.4.3: Congruent Angles and Angle Bisectors  CK12: Victor Cifarelli's "Geometry: Congruent Angles and Angle Bisectors"  Take notes as you read this section and watch the videos to learn about angle bisectors. This section provides examples identifying congruent angles and applying properties of an angle bisector. 
CK12: Victor Cifarelli's "Geometry: Congruent Angles and Angle Bisectors Practice"  These exercises will provide you with the opportunity to use properties of congruent angles and angle bisectors. 

1.4.4: Acute, Obtuse, and Right Angles  Khan Academy: "Acute, Right, and Obtuse Angles" and "Measuring Angles in Degrees"  Take notes as you watch these videos to learn how to identify acute, right, and obtuse angles. Watch the presentations carefully two or three times until you are able to identify types of angles. 
Khan Academy: "Angle Types"  Complete this assessment, which tests your knowledge on types of angles. You can review the concepts associated with these questions with the Khan videos in subunit 1.4.4. 

1.4.5: Complementary and Supplementary Angles  Khan Academy: "Complementary and Supplementary Angles" and "Identifying Complementary and Supplementary Angles"  Take notes as you watch these videos to learn how to identify supplementary and complementary angles. Watch the first presentation carefully to understand the basics of complementary, supplementary, adjacent, and straight angles. Watch the second presentations carefully two or three times until you are able to identify types of angles. 
CK12: Victor Cifarelli's "Geometry: Complementary Angles"  Complete the problems on complementary angles. You can refresh the page if you would like additional practice problems, and the questions will be different than the first set. 

CK12: Victor Cifarelli's "Geometry: Supplementary Angles"  Complete the problems on supplementary angles. You can refresh the page if you would like additional practice problems, and the questions will be different than the first set. 

Khan Academy: "Complementary and Supplementary Angles"  Complete this assessment, which tests your knowledge on complementary and supplementary angles. You can review the concepts associated with these questions with the Khan videos in subunit 1.4.5. 

1.4.6: Linear Pairs  CK12: Victor Cifarelli's "Geometry: Linear Pairs"  Take notes as you read this section and watch the videos to learn about linear pairs. This section provides examples of adjacent angles and angles that form a linear pair. Then, complete exercises 116 under "Explore more". These exercises will provide you with the opportunity to determine angles using linear pairs. Once you have completed the exercises, check your answers against the linked answer key. 
1.4.7: Vertical Angles  Khan Academy: "Angles at the Intersection of Two Lines"  Take notes as you watch this video to learn how vertical angles are equal to each other. Watch the presentation carefully two or three times to understand how vertical angles are equal. 
CK12: Victor Cifarelli's "Geometry: Vertical Angles"  Take notes as you read this section and watch videos to learn about linear pairs. This section provides examples of vertical angles and the vertical angles theorem. Then, complete exercises 114 under "Explore More". These exercises will provide you with the opportunity to determine angles using vertical angles. Once you have completed the exercises, check your answers against the linked answer key. 

Khan Academy: "Equation Practice with Vertical Angles"  Complete this assessment, which tests your knowledge on vertical angles. You can review the concepts associated with these questions with the Khan videos in subunit 1.4.7. 

1.5: Polygon Classification  CK12: Victor Cifarelli's "Geometry: "Classifying Polygons"  Study the "Points, Lines, and Planes" section. This section provides examples of various polygons and concave and convex polygons. Then, complete questions 114. These questions will provide you with the opportunity to identify polygons and apply polygon properties. 
Unit 2: Parallel and Perpendicular Lines  Unit 2 Learning Outcomes  
2.1.1: Parallel, Perpendicular, and Skew Lines  CK12: Victor Cifarelli's "Geometry: Lines and Angles"  Study the "Lines and Angles" section. This section provides examples of parallel, perpendicular, and skew lines. 
Khan Academy: "Identifying Parallel and Perpendicular Lines"  Take notes as you watch this video to learn how to identify parallel and perpendicular lines. Watch the presentation carefully two to three times to identify parallel and perpendicular lines. 

2.1.2: Angles and Transversals  CK12: Victor Cifarelli's "Geometry: Angles and Transversals"  Study this section. This section provides examples of different angles with a transversal line. 
CK12: Victor Cifarelli's "Geometry: Perpendicular Lines"  Study this section. This section provides examples of perpendicular lines. 

2.2.1: Corresponding Angles  CK12: Victor Cifarelli's "Geometry: Corresponding Angles"  Take notes as you watch the videos and read this section to learn about corresponding angles. This section provides examples of corresponding angles. Then, complete exercises 115. These exercises will provide you with the opportunity to determine angles using corresponding angles. Once you have completed the exercises, check your answers against the linked answer key. 
2.2.2: Alternate Interior Angles  CK12: Victor Cifarelli's "Geometry: Alternate Interior Angles"  Take notes as you watch the videos and read this section to learn about alternate interior angles. This section provides examples of corresponding angles. Then, complete exercises 115. These exercises will provide you with the opportunity to determine angles using alternate interior angles. Once you have completed the exercises, check your answers against the linked answer key. 
2.2.3: Alternate Exterior Angles  CK12: Victor Cifarelli's "Geometry: Alternate Exterior Angles"  Take notes as you watch the videos and read this section to learn about alternate exterior angles. This section provides examples of alternate exterior angles. Then, complete exercises 115. These exercises will provide you with the opportunity to determine angles using alternate exterior angles. Once you have completed the exercises, check your answers against the linked answer key. 
2.2.4: Same Side Interior Angles  CK12: Victor Cifarelli's "Geometry: Same Side Interior Angles"  Take notes as you watch the videos and read this section to learn about same side interior angles. This section provides examples of same side interior angles. Then, complete exercises 115. These exercises will provide you with the opportunity to determine angles using alternate exterior angles. Once you have completed the exercises, check your answers against the linked answer key. 
2.2.5: Angle Game  Khan Academy: "The Angle Game"  Take notes as you watch these videos to learn how to identify corresponding, alternate interior, alternate exterior, and same sideinterior angles. Watch the presentations carefully to understand the angle within each problem and how they are intertwined. 
Khan Academy: "Finding Angle Measures 1"  Complete this assessment, which tests your knowledge on corresponding, alternate interior, alternate exterior, and same side interior angles. You can review the concepts associated with these questions with the Khan videos in subsubunit 2.2.5. 

Khan Academy: "Finding Angle Measures 2"  Complete this assessment, which tests your knowledge on corresponding, alternate interior, alternate exterior, and same side interior angles. You can review the concepts associated with these questions with the Khan videos in subsubunit 2.2.5. 

2.3: Distance Formula in the Coordinate Plane  CK12: Victor Cifarelli's "Geometry: Distance Formula in the Coordinate Plane"  Take notes as you watch the videos and read this section to learn about find the distance between two points in the coordinate plane. This section provides examples of find the distance between two points in the coordinate plane. Then, complete exercises 18 and 13. These exercises will provide you with the opportunity to find the distance between two points in the coordinate plane. Once you have completed the exercises, check your answers against the linked answer key. 
Unit 3: Triangles, Congruence, and Other Relationships  Unit 3 Learning Outcomes  
3.1: Triangle Classification  CK12: Victor Cifarelli's "Geometry: Triangle Classification"  Take notes as you watch the videos and read this section to learn about classifying triangles based on angles and sides. This section provides examples of triangle classification. Then, complete the interactive practice and "explore more" problems. 
Khan Academy: "Triangle Types"  Complete this assessment, which tests your knowledge on triangle classification. You can review the concepts associated with these questions with the material in subunit 3.1. 

3.2.1: Triangle Sum Theorem  CK12: Victor Cifarelli's "Geometry: Triangle Sum Theorem"  Take notes as you watch the videos and read this section to learn about the sum of the interior angles of a triangle. This section provides examples of finding angles within a triangle. Then, complete exercises 115. These exercises will provide you with the opportunity to find the missing angle(s) of triangles. Once you have completed the exercises, check your answers against the linked answer key. 
3.2.2: Exterior Angle Theorem  CK12: Victor Cifarelli's "Geometry: Exterior Angle Theorem"  Take notes as you watch the videos and read this section to learn about the exterior angles and the relationship with triangles. This section provides examples of how to find the missing interior and exterior angles of a triangle. Then, complete exercises 112. These exercises will provide you with the opportunity to find the missing angles of triangles as well as exterior angles. Once you have completed the exercises, check your answers against the linked answer key. 
3.2.3: Triangle Examples  Khan Academy: "Triangle Angle Examples"  Take notes as you watch these videos to learn how to find missing angles of triangles by applying various properties. Watch the presentations carefully to understand how to find the missing angles of multiple triangles. 
Khan Academy: "Triangle Angles"  Complete this assessment, which tests your knowledge on vertical angles. You can review the concepts associated with these questions with the material in subsubunits 3.2.1 and 3.2.2. 

3.3.1: Congruent Figures  CK12: Victor Cifarelli's "Geometry: Congruent Figures"  Study the "Congruent Figures" section. This section provides discussions on defining and writing congruence statements in triangles, the third angle theorem, and congruence properties. Then, complete the review questions. These exercises will provide you with the opportunity to identify congruent figures and explain why certain triangles are congruent. 
3.3.2: Congruent Triangles and SSS  Khan Academy: "Congruence Triangles and SSS"  Take notes as you watch this video to review the properties of congruent triangles as well as the SideSideSide (SSS) Congruent Postulate for Triangles. Watch the presentation carefully two or three times to understand how to triangles are congruent by sidesideside. 
CK12: Victor Cifarelli's "Geometry: Triangle Congruent Using SSS"  Study this section. This section provides the reasons why two triangles are congruent by using SSS. Then, complete the practice questions, which will provide you with the opportunity to identify congruent triangles by using SSS. 

3.3.3: Other Triangle Congruent Postulates  Khan Academy: "Other Triangle Congruence Postulates"  Take notes as you watch this video to prove triangles are congruent by using the following postulates: SideAngleSide (SAS), AngleSideAngle (ASA), and AngleAngleSide (AAS). Watch the presentation carefully two or three times to understand how two triangles are congruent by these three congruence properties. 
CK12: Victor Cifarelli's "Geometry: Triangle Congruence"  Study this section. This section provides the reasons why two triangles are congruent by using ASA and AAS. Then, complete the review questions, which will provide you with the opportunity to identify congruent triangles by using ASA and AAS. 

CK12: Victor Cifarelli's "Geometry: HL Triangle Congruence"  Read this section. This section provides you with the reasons why two triangles are congruent by using HL. Then, complete the review questions. 

3.3.4: More on Why SSA Is Not a Postulate  Khan Academy: "More on Why SSA Is Not a Postulate"  Take notes as you watch this video to show why SideSideAngle cannot prove two triangles to be congruent. Watch the presentation carefully two or three times to understand how two triangles are not congruent by sidesideangle. 
CK12: Victor Cifarelli's "Geometry: Possible Triangles with SideSideAngle"  Read this section. This section provides the reasons why two triangles are not congruent by using AAA and SSA. 

3.3.5: Finding Congruent Triangles  Khan Academy: "Finding Congruent Triangles"  Take notes as you watch this video to determine which congruent triangle postulate proves two triangles to be congruent. Watch the presentation carefully two or three times to understand if two triangles are congruent by SSS, ASA, SAS, or AAS. 
Khan Academy: "Congruent Triangles 1"  Complete this assessment, which tests your knowledge on congruent triangles using the triangle congruence postulates. You can review the concepts associated with these questions with the Khan videos in subsubunits 3.3.23.3.5. 

Khan Academy: "Congruent Triangles 2"  Complete this assessment, which tests your knowledge on congruent triangles using the triangle congruence postulates. You can review the concepts associated with these questions with the Khan videos in subsubunits 3.3.23.3.5. 

3.4: Isosceles Triangles  CK12: Victor Cifarelli's "Geometry: Isosceles Triangles"  Take notes as you watch the videos and read this section to learn about the isosceles triangles angles and their properties. This section provides examples of how to find the missing sides and angles of an isosceles triangle. Then, complete the review questions. 
Khan Academy: "Another Isosceles Example Problem"  Take notes as you watch this video to determine the missing sides and angles of an isosceles triangle. Watch the presentation carefully two or three times to understand on how to write algebraic equations to find the missing angles and sides of an isosceles triangle. 

3.5: Equilateral Triangles  CK12: Victor Cifarelli's "Geometry: Equilateral Triangles"  Take notes as you watch the videos and read this section to learn about the equilateral triangles angles and their properties. This section provides examples of find the missing sides and angles of an equilateral triangle. Then, complete exercises 115. These exercises will provide you with the opportunity to find the missing angles and sides of isosceles triangles. Once you have completed the exercises, check your answers against the linked answer key. 
Unit 4: Triangle Relationships  Unit 4 Learning Outcomes  
4.1: Midsegment Theorem  CK12: Victor Cifarelli's "Geometry: Midsegments of a Triangle"  Study this section which provides examples and definitions of the midsegments of a triangle. Then, complete the review questions. These questions will provide you with the opportunity to find the midsegments of a triangle. 
4.2: Perpendicular Bisectors  CK12: Victor Cifarelli's "Geometry: Perpendicular Bisectors"  Take notes as you read this section and watch the videos to learn about perpendicular bisectors and their properties. This section provides examples of find the missing sides and angles of an equilateral triangle. Then, complete the review exercises. These exercises will provide you with the opportunity to apply the properties of perpendicular bisectors. 
4.3: Angle Bisectors in Triangles  CK12: Victor Cifarelli's "Geometry: Angle Bisectors in Triangles"  Take notes as you read this section and watch the videos to learn about angle bisectors in triangles. This section provides examples of how to find the missing angles by using properties of an angle bisector. Then, complete the review exercises. These exercises will provide you with the opportunity to apply the properties of angle bisectors. 
4.4: Medians  CK12: Victor Cifarelli's "Geometry: Medians in Triangles"  Study this section. This section provides examples and a definition of the median in a triangle. Then, complete the review questions, which will provide you with the opportunity to find the medians and the centroid of a triangle. 
Khan Academy: "Median Centroid Right Triangle Example"  Take notes as you watch this video to determine the length of the median of a triangle. Watch the presentation carefully two or three times to understand the centroid and properties of a median. 

4.5: Altitudes  CK12: Victor Cifarelli's "Geometry: Altitudes in Triangles"  Take notes as you watch the videos and read this section to learn about altitudes in triangles. Read the overview until you are able to understand altitudes within triangles. This reading also provides examples of how to find the altitude of a triangle. Then, complete the review questions and check your answers. 
4.6.1: Triangle Inequality Theorem  CK12: Victor Cifarelli's "Geometry: Triangle Inequality Theorem"  Take notes as you watch the videos and read this section to learn about the triangle inequality theorem. This section provides applications of the triangle inequality theorem, which states that any side of a triangle must be equal to or less than the sum of the other two sides in order to form the triangle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the triangle inequality theorem. 
4.6.2: Inequalities in Two Triangles  CK12: Victor Cifarelli's "Geometry: Triangle Inequality Theorem"  Watch the videos and read this section. This section provides examples and definitions of triangle inequality theorems. Then, complete the review questions. These questions will provide you with the opportunity to apply the inequality triangle theorems. 
Khan Academy: "Triangle Inequality Theorem"  Complete this assessment, which tests your knowledge on the triangle inequality theorem. You can review the concepts associated with these questions with the content from subsubunit 4.6.1 and 4.6.2. 

Unit 5: Polygons and Quadrilaterals  Unit 5 Learning Outcomes  
5.1: Sum of Interior Angles of a Polygon  Khan Academy: "Sum of Interior Angles of a Polygon"  Take notes as you watch this video to determine how to find the sum of the interior angles of a polygon. Watch the presentation carefully two or three times to understand how to determine the sum of the interior angles of a polygon. 
CK12: Victor Cifarelli's "Geometry: Interior Angles"  Read this section, which provides examples of how to find the sum of the interior angles of a polygon. Then, complete the review questions, which will provide you with the opportunity to apply the sum of interior angles of a polygon. 

5.2: Sum of Exterior Angles of a Convex Polygon  Khan Academy: "Sum of Exterior Angles of a Convex Polygon"  Take notes as you watch this video to determine how to find the sum of the exterior angles of a polygon. Watch the presentation carefully two or three times to understand how to determine the sum of the exterior angles of a polygon. 
CK12: Victor Cifarelli's "Geometry: Exterior Angles"  Read this section, which provides examples of how to find the sum of the exterior angles of a polygon. Then, answer the review questions, which will provide you with the opportunity to apply the sum of exterior angles of a polygon. 

Khan Academy: "Angles of a Polygon"  Complete this assessment, which tests your knowledge on the interior and exterior angles of a polygon. You can review the concepts associated with these questions with the content from subunit 5.1 and 5.2. 

5.3: Parallelograms  CK12: Victor Cifarelli's "Geometry: Parallelograms"  Take notes as you watch the videos and read this section to learn about the properties of a parallelogram. This section provides examples of applying parallelogram properties. Then, complete the practice problems, which will provide you with the opportunity to apply the parallelogram properties. 
5.4: Parallelogram Classification  CK12: Victor Cifarelli's "Geometry: Parallelogram Classification"  Take notes as you watch the videos to learn about classifying other parallelogram and their properties. This section provides examples of applying parallelogram properties. Then, complete the practice problems, which will provide you with the opportunity to apply the parallelogram properties. 
5.5: Trapezoids  CK12: Victor Cifarelli's "Geometry: Trapezoids"  Take notes as you watch the videos and read this section to learn about trapezoids and their properties. This section provides examples of applying trapezoid properties. Then, complete the practice problems, which will provide you with the opportunity to apply the parallelogram properties. 
5.6: Kites  CK12: Victor Cifarelli's "Geometry: Kites"  Take notes as you watch the videos to learn about kites and their properties. This section provides examples of applying kite properties. Then, complete the practice problems, which will provide you with the opportunity to apply the kite properties. 
5.7.1: Coordinate Geometry  CK12: Victor Cifarelli's "Geometry: Quadrilateral Classification"  Take notes as you watch the videos and read this section to learn about classifying quadrilaterals using coordinate geometry. This section provides examples of applying these properties to determine the quadrilateral. Then, complete the practice problems, which will provide you with the opportunity to apply the properties of quadrilaterals. 
5.7.2: Quadrilateral Overview  Khan Academy: "Quadrilateral Overview and Properties"  Take notes as you watch these videos to recognize various special parallelograms. Watch these presentations carefully two or three times to understand how to determine various parallelograms. 
Khan Academy: "Quadrilateral Types Exercise"  Complete this assessment, which will test your knowledge on the types of polygons. You can review the concepts associated with these questions with the content from subsubunit 5.7.2. 

Khan Academy: "Quadrilateral and Polygons Challenge"  Complete this assessment, which will test your knowledge on the types of polygons. You can review the concepts associated with these questions with the content from subsubunit 5.7.2. 

Unit 6: Similarity  Unit 6 Learning Outcomes  
6.1: Similar Polygons  Khan Academy: "Similar Triangle Basics"  Take notes as you watch this video to understand properties of similar triangles. Watch this presentation carefully two or three times to understand what the relationship is between sides and angles of similar figures. 
CK12: Victor Cifarelli's "Geometry: Similar Polygons and Scale Factors"  Take notes as you watch the videos and read this section to learn about similar polygons and scale factor. This section provides examples of applying these properties to similar figures. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the properties of similar figures. 

Khan Academy: "Similar Triangles 1"  Complete this assessment, which tests your knowledge of similar triangles and their properties. You can review the concepts associated with these questions with the content from subunit 6.1. 

Khan Academy: "Similar Triangles 2"  Complete this assessment, which tests your knowledge of similar triangles and their properties. You can review the concepts associated with these questions with the content from subunit 6.1. 

6.2: Similarity Postulates  Khan Academy: "Similarity Postulates"  Take notes as you watch this video to understand postulates of similar triangles. Watch this presentation carefully two or three times to understand how to determine similarity postulates of similar triangles. 
6.2.1: AngleAngle (AA) Similarity and Indirect Measurement  Khan Academy: "Similarity Triangle Example Problems"  Take notes as you watch this video to understand sample problems of similar triangles. Watch this presentation carefully two or three times to understand how to find missing sides and angles of similar triangles. 
CK12: Victor Cifarelli's "Geometry: Similarity by AA"  Read this section, which provides examples of how to prove triangles are similar by AA and how to indirectly measure items. Then, complete the practice problems. These exercises will provide you with the opportunity to apply AA similarity and indirect measurement. 

6.2.2: SideSideSide (SSS) Similarity and SideAngleSide (SAS) Similarity  CK12: Victor Cifarelli's "Geometry: Similarity by SSS"  Read this section, which provides examples of how to prove triangles are similar by SSS and how to find missing parts of similar triangles. Then, complete the practice problems. These questions will provide you with the opportunity to apply SSS similarity. 
CK12: Victor Cifarelli's "Geometry: Similarity by SAS"  Read this section, which provides examples of how to prove triangles are similar by SAS and how to find missing parts of similar triangles. Then, complete the practice problems. These questions will provide you with the opportunity to apply SAS similarity. 

6.3: Triangle Proportionality and Parallel Lines and Transversals  Khan Academy: "Similarity Example Problems"  Take notes as you watch this video to understand sample problems of similar triangles. Watch this presentation carefully two or three times to understand how to find missing sides and angles of similar triangles. 
CK12: Victor Cifarelli's "Geometry: Proportionality Relationships"  Read this section, which provides examples of how to find missing parts of similar triangles in other forms. Then, complete the practice problems. These questions will provide you with the opportunity to apply proportionality relationships. 

Khan Academy: "Solving Similar Triangles 1"  Complete this assessment, which tests your knowledge on finding missing sides and angles of similar triangles. You can review the concepts associated with these questions with the content from subunits 6.2 and 6.3. 

Khan Academy: "Solving Similar Triangles 2"  Complete this assessment, which tests your knowledge on finding missing sides and angles of similar triangles. You can review the concepts associated with these questions with the content from subunits 6.2 and 6.3. 

6.4: Proportions with Angle Bisectors  CK12: Victor Cifarelli's "Geometry: Proportions with Angle Bisectors"  Take notes as you watch the videos and read this section to learn about proportions with angle bisectors in triangles. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the properties of the triangle angle bisectors theorem. 
Unit 7: Right Triangle Trigonometry  Unit 7 Learning Outcomes  
7.1: Pythagorean Theorem  Khan Academy: "Pythagorean Theorem"  Take notes as you watch this video to understand the Pythagorean Theorem. Watch this presentation carefully two or three times to understand how to find missing sides by using this formula. 
CK12: Victor Cifarelli's "Geometry: Pythagorean Theorem and Pythagorean Triples"  Read this section, which provides examples of applying the Pythagorean Theorem. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the Pythagorean Theorem. 

CK12: Victor Cifarelli's "Geometry: Converse of the Pythagorean Theorem"  Read this section, which discusses how to identify triangle types from the Pythagorean Theorem. Then, complete the practice problems. These questions will provide you with the opportunity to determine triangles by using the Pythagorean Theorem. 

7.2: 454590 Triangles  Khan Academy: "454590 Triangles"  Take notes as you watch this video to understand the relationship between the angles and sides of a 454590 triangle. Watch this presentation carefully two or three times to understand how to find missing sides using this triangle. 
CK12: Victor Cifarelli's "Geometry: 454590 Right Triangles"  Read this section, which discusses 454590 right triangles. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the relationship between the sides of a 454590 right triangle. 

7.3: 306090 Right Triangles  Khan Academy: "306090 Triangles II"  Take notes as you watch this video to understand the relationship between the angles and sides of a 306090 triangle. Watch this presentation carefully two or three times to understand how to find missing sides by applying the properties of this triangle. 
CK12: Victor Cifarelli's "Geometry: 306090 Right Triangles"  Read this section, which discusses 306090 right triangles. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the relationship between the sides of a 306090 right triangle. 

Khan Academy: "Special Right Triangles"  Complete this assessment, which tests your knowledge on finding the missing sides of special right triangles. You can review the concepts associated with these questions with the Khan videos from subunits 7.2 and 7.3. 

7.4: Sine, Cosine, and Tangent  CK12: Victor Cifarelli's "Geometry: Sine, Cosine, and Tangent"  Read this section, which discusses trigonometric ratios. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the relationships of various trigonometric ratios. 
Khan Academy: "Trigonometric Ratios in Right Triangles"  Complete this assessment, which tests your knowledge on basic trigonometric ratios. You can review the concepts associated with these questions from subunit 7.4. 

7.5: Trigonometric Ratios with a Calculator  CK12: Victor Cifarelli's "Trigonometric Ratios with a Calculator"  Read this section, which discusses finding trigonometric ratios with a calculator. Then, complete the practice problems. These exercises will provide you with the opportunity to use a calculator to find various trigonometric ratios. 
Unit 8: Circles  Unit 8 Learning Outcomes  
8.1: Language and Notation of a Circle  Khan Academy: "Language and Notation of a Circle"  Take notes as you watch this video to understand the language and notation associated with a circle. Watch this presentation carefully two or three times to understand how to identify parts of a circle. 
CK12: Victor Cifarelli's "Geometry: Parts of a Circle"  Take notes as you watch the videos and read this section to learn about how to recognize various parts of a circle. Then, complete the practice problems. These exercises will provide you with the opportunity to recognize various parts of a circle. 

8.2: Tangent Lines  CK12: Victor Cifarelli's "Geometry: Tangent Lines"  Take notes as you watch the videos and read this section to learn how to identify tangent lines and their properties. Then, complete the practice problems. These questions will provide you with the opportunity to apply properties of tangent lines and circles. 
8.3: Arcs in Circles  CK12: Victor Cifarelli's "Geometry: Arcs in Circles"  Take notes as you watch the videos and read this section to learn about arcs in a circle. Then, complete the practice problems. These exercises will provide you with the opportunity to recognize various parts of a circle. 
8.4: Chords in Circles  CK12: Victor Cifarelli's "Geometry: Chords in Circles"  Take notes as you watch the videos and read this section to learn about how to recognize chords. Then, complete the practice problems. These exercises will provide you with the opportunity to apply theorems related to chords. 
8.5: Inscribed Angles  CK12: Victor Cifarelli's "Geometry: Inscribed Angles in Circles"  Take notes as you watch the videos and read this section to learn about inscribed angles in circles and their properties. Then, complete the practice problems. These exercises will provide you with the opportunity to apply properties of inscribed angles. 
8.6: Angles of Chords, Secants, and Tangents  CK12: Victor Cifarelli's "Geometry: Angles of Chords, Secants, and Tangents"  Take notes as you read this section to learn about inscribed angles of chords, secants, and tangents. Then, complete the practice problems. These exercises will provide you with the opportunity to apply properties of angles of chords, secants, and tangents. 
8.7: Segments of Chords, Secants, and Tangents  CK12: Victor Cifarelli's "Geometry: Segments of Chords, Secants, and Tangents"  Take notes as you read these sections to learn about segments of chords, secants, and tangents. Then, complete the practice problems. These questions will provide you with the opportunity to apply properties of segments of chords, secants, and tangents. 
Unit 9: Perimeter and Area  Unit 9 Learning Outcomes  
9.1: Perimeter and Area Basics  Khan Academy: "Perimeter and Area Basics"  Take notes as you watch this video to understand the basics of area and perimeter. Watch this presentation carefully two or three times to understand how to determine difference of the area and perimeter. 
9.2: Area of Triangles  Khan Academy: "Area and Perimeter"  Take notes as you watch this video to understand the basics of finding the area and perimeter of a triangle. Watch this presentation carefully two or three times to understand how to find the area and perimeter of a triangle. 
CK12: Victor Cifarelli's "Geometry: Area and Perimeter of a Triangle"  Take notes as you watch the video and read this section to learn about area and perimeter of a triangle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area and perimeter of a triangle. 

Khan Academy: "Area of Triangles"  Complete this assessment, which tests your knowledge on the area of triangles. You can review the concepts associated with these questions from subunit 9.2. 

9.3: Area and Perimeter of Rectangles and Squares  CK12: Victor Cifarelli's "Geometry: Area and Perimeter of a Rectangle"  Take notes as you watch the video and read this section to learn about area and perimeter of a rectangle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area and perimeter of a rectangle. 
Khan Academy: "Area of Squares and Rectangles"  Complete this assessment, which tests your knowledge on the area of squares and rectangles. You can review the concepts associated with these questions from subunit 9.3. 

9.4: Area of a Parallelogram  CK12: Victor Cifarelli's "Geometry: Area of a Parallelogram"  Take notes as you watch the video and read this section to learn about area of a parallelogram. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area of a parallelogram. 
9.5: Area and Perimeter of Trapezoids  CK12: Victor Cifarelli's "Geometry: Area and Perimeter of Trapezoids"  Take notes as you watch the video and read this section to learn about area and perimeter of trapezoids. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area and perimeter of trapezoids. 
9.6: Area and Perimeter of Rhombuses and Kites  CK12: Victor Cifarelli's "Geometry: Area and Perimeter of Rhombuses and Kites"  Take notes as you watch the video and read this section to learn about area and perimeter of rhombuses and kites. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area and perimeter of rhombuses and kites. 
Khan Academy: "Area of Trapezoids, Rhombi, and Kites"  Complete this assessment, which tests your knowledge on the area of trapezoids, rhombi, and kites. You can review the concepts associated with these questions from subunits 9.5 and 9.6. 

9.7: Area and Perimeter of Similar Polygons  CK12: Victor Cifarelli's "Geometry: Area and Perimeter of Similar Polygons"  Take notes as you watch the video and read this section to learn about area and perimeter of similar polygons. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area and perimeter of similar polygons. 
9.8: Circumference  CK12: Victor Cifarelli's "Geometry: Circumference"  Take notes as you watch the video and read this section to learn about the circumference of a circle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for circumference of a circle. 
9.9: Arc Length  CK12: Victor Cifarelli's "Geometry: Arc Length"  Take notes as you watch the video and read this section to learn about the arc length of a circle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for arc length of a circle. 
9.10: Area of a Circle  CK12: Victor Cifarelli's "Geometry: Area of a Circle"  Take notes as you watch the video and read this section to learn about the area of a circle. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for area of a circle. 
Khan Academy: "Area of a Circle"  Complete this assessment, which tests your knowledge on the area of circles. You can review the concepts associated with these questions from subunit 9.10. 

9.11: Area of Composite Shapes  Khan Academy: "Perimeter and Area of a NonStandard Polygon"  Take notes as you watch this video to understand the basics of finding the area of composite shapes. Watch this presentation carefully two or three times to understand how to find the area of composite figures. 
CK12: Victor Cifarelli's "Geometry: Area of Composite Shapes"  Take notes as you watch the video and read this section to learn about the areas of composite figures. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for areas of composite figures. 

Unit 10: Surface Area and Volume  Unit 10 Learning Outcomes  
10.1: Polyhedrons  CK12: Victor Cifarelli's "Geometry: Polyhedrons"  Read this section, which defines various terms associated with polyhedron. Then, complete the practice problems. These questions will provide you with the opportunity to apply properties of threedimensional figures. 
10.2: Representing Solids  CK12: Victor Cifarelli's "Geometry: Representing Solids"  Read this section, which defines various terms and methods associated with representing solids. Then, complete the practice problems. These questions will provide you with the opportunity to apply properties of representing solids. 
10.3: Prisms  CK12: Victor Cifarelli's "Geometry: Prisms"  Read this section, which discusses the surface area and volume of prisms. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas for surface area and volumes of prisms. 
10.4: Cylinders  CK12: Victor Cifarelli's "Geometry: Cylinders"  Read this section, which discusses the surface area and volume of cylinders. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas to find the surface areas and volumes of cylinders. 
10.5: Pyramids  CK12: Victor Cifarelli's "Geometry: Pyramids"  Read this section, which discusses the surface area and volume of pyramids. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas to find the surface areas and volumes of pyramids. 
10.6: Cones  CK12: Victor Cifarelli's "Geometry: Cones"  Read this section, which discusses the surface area and volume of cones. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas to find the surface areas and volumes of cones. 
10.7: Spheres  Khan Academy: "Solid Geometry"  Complete this assessment, which tests your knowledge on surface area and volume. You can review the concepts associated with these questions with the content in subunits 10.310.7. 
CK12: Victor Cifarelli's "Geometry: Spheres"  Read this section, which discusses the surface area and volume of spheres. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas to find the surface areas and volumes of spheres. 

10.8: Composite Solids  CK12: Victor Cifarelli's "Geometry: Composite Solids"  Read this section, which discusses the surface area and volume of composite solids. Then, complete the practice problems. These exercises will provide you with the opportunity to apply the formulas to find the surface areas and volumes of composite solids. 
Optional Course Evaluation Survey  Optional Course Evaluation Survey  Please take a few moments to provide some feedback about this course. Consider completing the survey whether you have completed the course, you are nearly at that point, or you have just come to study one unit or a few units of this course. Your feedback will focus our efforts to continually improve our course design, content, technology, and general easeofuse. Additionally, your input will be considered alongside our consulting professors' evaluation of the course during its next round of peer review. As always, please report urgent course experience concerns to [email protected] and/or our discussion forums. 