please help me!!!

Question

1. from the top of a 150 ft building , polly observes tony driving a car toward her. If the angle of depression to the car changes from 18 deg to 42 deg during the observation, how far does the car travel?

Answer 1

Drawing the figure with the depression angles, the distance between the ground level angles which are equal to the depression angles, you have two formulas:

d18 = distance the car is from the edge of the building when first observed = 150Cos(18°)

d42 = distance the car is from the edge of the building after the observation period = 150Cos(42)

d18-d42 is the distance traveled during the observation

d18-d42 = 150(Cos18)-Cos42) = 31.2 feet.