### Unit 5: Polygons and Quadrilaterals

Polygons are everywhere around us. If you see a shape that has no curves, then it is a polygon. As a child, you probably learned the names of many common polygons. In this unit, you will focus on quadrilaterals, which are polygons with four sides. They each have their own set of characteristics and share some characteristics with other quadrilaterals. You will learn to recognize these characteristics and to use them to help you answer questions about quadrilaterals.

**Completing this unit should take you approximately 12 hours.**

Upon successful completion of this unit, you will be able to:

- find the measure of interior angles of polygons;
- find the measure of exterior angles of polygons;
- use various theorems to algebraically find missing sides and/or angles in polygons; and
- classify quadrilaterals.

### 5.1: 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.

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

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.

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.

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

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

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

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

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: Quadrilateral Classification

### 5.7.1: Coordinate Geometry

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

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.

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 sub-subunit 5.7.2.

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 sub-subunit 5.7.2.