### Home > PC > Chapter 5 > Lesson 5.2.4 > Problem5-89

5-89.

Evaluate the trig expressions below.

1. $\cos 60°$

1. $\sin \frac { 3 \pi } { 4 }$

1. $\sin \frac { 3 \pi } { 2 }$

1. $\cos 90°$

Sketch a unit circle for each plotting the point and labeling the sides of the reference triangle.