1. Measuring Angles

The measures of two angles of a triangle are given. Find the measure of the third angle. See Example 2. 37° , 52°

Find the measure of each marked angle. See Example 2.

Find the unknown side lengths in each pair of similar triangles. See Example 4.

Find each exact function value. See Example 3.

cos 3π

The measures of two angles of a triangle are given. Find the measure of the third angle. See Example 2.

17° 41' 13" , 96° 12' 10"

In Exercises 65–66, an object moves in simple harmonic motion described by the given equation, where t is measured in seconds and d in centimeters. In each exercise, find: a. the maximum displacement b. the frequency c. the time required for one cycle. d = 20 cos π/4 t

Solve each problem. Length of a Road A camera is located on a satellite with its lens positioned at C in the figure. Length PC represents the distance from the lens to the film PQ, and BA represents a straight road on the ground. Use the measurements given in the figure to find the length of the road. (Data from Kastner, B., Space Mathematics, NASA.)

Find the measure of (a) the complement and (b) the supplement of an angle with the given measure. See Examples 1 and 3. 45°

Work each problem.

Consider each angle in standard position having the given radian measure. In what quadrant does the terminal side lie?

7

Convert each radian measure to degrees.

-11π/18

Find the measure of each marked angle.

Concept Check Classify each triangle as acute, right, or obtuse. Also classify each as equilateral, isosceles, or scalene. See the discussion following Example 2.

Find each exact function value. See Example 3.

sin (-7π/ 6)

Concept Check Classify each triangle as acute, right, or obtuse. Also classify each as equilateral, isosceles, or scalene. See the discussion following Example 2.

Convert each degree measure to radians. Leave answers as multiples of π .

45°