Answer:
[tex]31,387\:\text{ft}[/tex]
Step-by-step explanation:
We can form a right triangle using the plane, the airport, and ground and use basic trig for a right triangle to solve this problem.
In a right triangle, [tex]\tan\theta=\frac{\text{opp}}{\text{adj}}[/tex]. Therefore, we have the following equation, where [tex]x[/tex] is ground distance between the plane and the airport:
[tex]\tan 16^{\circ}=\frac{9,000}{x},\\x=\frac{9,000}{\tan 16^{\circ}},\\x\approx \boxed{31,387\:\text{ft}}[/tex].