An observer on the ground at point A watches a rocket ascend. The observer is 1200 feet from the launch point B. As the rocket rises, the distance d from the observer to the rocket increases.

Question

An observer on the ground at point A watches a rocket ascend. The observer is 1200 feet from the launch point B. As the rocket rises, the distance d from the observer to the rocket increases. 
a. Express the measure of angle A in terms of d. 
b. Find the measure of angle A if d = 1500 feet. 
c. Find the measure of angle A if d = 2000 feet.

Steve · Answer

cosA = 1200/d Now just plug in the values for d to find cosA.