Answer:
43314.76 ft horizontally he must fly to be directly over the runway
Explanation:
Refer the figure given
We have altitude of aeroplane = BC = 10000 ft
The pilot notices that the beginning of the runway where he plans to land is at an angle of depression of 13 degrees with the horizontal
∠CAB = 13°
We need to find how far horizontally must he fly to be directly over the runway = AB
We have

43314.76 ft horizontally he must fly to be directly over the runway