Question 914195
Two stations A and B are 2,000m apart.
 When an airplane was directly above A, an observer at B found that the angle of elevation of the airplane is 60°
 How far is the plane from the station B??
:
A right triangle is formed by A, B, and the plane. The distance from B to the plane is the hypotenuse (h)
Use the cosine; side adjacent/hypotenuse
cos(60) = {{{2000/h}}}
h = {{{2000/cos(60)}}}
h = 4000 meters from B to the plane