Learning Objectives

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

• Use right triangles to evaluate trigonometric functions.
• Find function values for $30^\circ \left(\frac{\pi }{6}\right)$, $45^\circ \left(\frac{\pi }{4}\right)$, and $60^\circ \left(\frac{\pi }{3}\right)$.
• Use cofunctions of complementary angles.
• Use the definitions of trigonometric functions of any angle.
• Use right triangle trigonometry to solve applied problems.