Answer:
47,433.0 feet
Explanation:
Using the SOH CAH TOA identity
Height of the plane = opposite = 17000feet
distance between the plane and the airport = hypotenuse = x
Angle of depression = 21 degrees
Since Sin theta = opp/hyp
Sin 21 = 17000/x
x = 17000/sin21
x = 17000/0.3584
x = 47,433.0
Hence the distance between the plane and the airport to the nearest 10th of a foot is 47,433.0 feet