Question

When a 757 passenger jet begins its descent to the Ronald Reagan National Airport in Washington, D.C., it is 3900 feet from the ground. Its angle of descent is 6º.

How far must the plane fly to reach the runway?

Answer 1

B. 37,310.4 ft

Explanation:

It's a rectangle triangle, and we have the height (3900 ft) and the opposite angle (6 degrees), and we're looking for the hypotenuse (distance traveled) length.

In a rectangle triangle, there's a relation between those elements: the sinus of the angle.

`sin(angle) = (Opposite side)/(Hypotenuse)`

So, if we want to calculate the hypotenuse...

`Hypotenuse = (Opposite side)/(sin(angle))\ = (3900 ft)/(sin(6))\ = (3900 ft)/(0.1045)\ = 37310.4117 ft`