Question

An airplane is flying 38,900 ft above the ground. Angle of depression from the plane to the base of the building is 4.3°. How far must a plane fly horizontally to be directly over the building?

Answer 1

Height of the airplane above the ground = 38,900 ft.

Angle of depression from the plane to the base of the building = 4.3°.

So, we could apply tangent trigonometric ratio:

$tan 4.3 = \frac{Height}{Base}$

tan 4.3° = $\frac{38,900}{x}$

0.07519 = $\frac{38,900}{x}$

On cross multiply, we get

0.07519 x= 38,900.

Dividing both sides by 0.07519, we get

x= 517356.03 ft.

Therefore, the plane must fly 517356.03 ft. horizontally to be directly over the building.