• ### Unit 7: Right Triangle Trigonometry

In this unit we, will explore basic trigonometry. We use trigonometry for several types of measuring techniques, such as calculating the height of a building when you know how far away you are standing from a building and the angle of your gaze to the top. Sailors used trigonometry to determine distances and set their course by using the stars as their guide.

Completing this unit should take you approximately 3 hours.

• ### 7.1: The Pythagorean Theorem

The Pythagorean theorem allows us to calculate the lengths of the sides of a triangle. We use it frequently to solve for the unknown length of a side of a triangle.

• ### 7.2: 45-45-90 Triangles

Now that we know the general form of the Pythagorean theorem and how to use it, we can begin exploring special types of triangles and their properties. The first type of triangle we will study is the 45-45-90 right triangle, which is also known as an isosceles triangle.

• ### 7.3: 30-60-90 Right Triangles

The other type of right triangle are 30-60-90 right triangles. These triangles have the special property that their side lengths are always related by a specific ratio.

• ### 7.4: Sine, Cosine, and Tangent

When performing calculations with triangles, as we have seen, we often are interested in ratios between lengths of the sides of the triangle. The study of trigonometry is the study of these ratios.

• ### 7.5: Trigonometric Ratios with a Calculator

Finally, we need to learn to use a calculator to solve for sine, cosine, and tangent.