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Module 2: The Unit Circle & Right Triangle Trigonometry

Define the trig functions using the unit circle, evaluate them at special angles, and solve right triangles.

4 Lessons
~3-4 hours
10 Practice Problems
Module Quiz

Learning Objectives

By the end of this module, you will be able to:

  • Define sine and cosine using the unit circle
  • Evaluate trig functions at special angles (0, π/6, π/4, π/3, π/2) and their multiples
  • Apply right triangle definitions (SOH-CAH-TOA) to find sides and angles
  • Solve right triangles and real-world application problems

Module Lessons

1

Defining Sine and Cosine on the Unit Circle

Learn how the unit circle provides a geometric definition for sine and cosine for any angle.

30-35 minutes

2

Evaluating Trig Functions at Special Angles

Memorize and apply the trig values at key angles using the unit circle.

35-40 minutes

3

Right Triangle Definitions of Trig Functions

Define all six trig functions using the sides of a right triangle (SOH-CAH-TOA).

25-30 minutes

4

Solving Right Triangles and Applications

Use trig functions to find missing sides and angles; apply to elevation, depression, and navigation problems.

30-35 minutes

After the Lessons

Practice Problems

10 problems covering the unit circle, special angles, and right triangle applications.

Practice Problems

Module Quiz

10-question quiz to test your mastery of unit circle and right triangle trig.

Take Module Quiz
Begin Module 2 →