Unit B: Right Triangles
Chapter 4:Trigonometry


Lesson 2: The Sine and Cosine Ratios

In the previous lesson, you learned that one of the acute angles in a right triangle and the lengths of the legs of that right triangle are related by the tangent ratio. Do you think there is a relationship that uses the longest side of a right triangle, the hypotenuse?


Here are the things you will do in this lesson:

  • Learn about the sine and cosine ratios of right triangles
  • Discover how the sine and cosine ratios can be used to determine unknown lengths and angle measures in right triangles.


2014 © Alberta Distance Learning Centre