Answer:
[tex]7.4^{o}[/tex]
Step-by-step explanation:
Altitude of the plane = 4 miles
Distance from the plane to the airport = 31 miles
Let the angle of depression from the plane to the airport be represented by θ. Thus applying the appropriate trigonometric function, we have;
Tan θ = [tex]\frac{opposite}{adjacent}[/tex]
= [tex]\frac{4}{31}[/tex]
= 0.1290
θ = [tex]Tan^{-1}[/tex] 0.1290
= 7.3506
θ = [tex]7.4^{o}[/tex]
The angle of depression from the plane to the airport is [tex]7.4^{o}[/tex].