You are looking at a billboard 40m away with an angle of elevation of 30°. At what height is the billboard?

A 20

B 30

C 40

D 50

Correct Answer: Option A

Let, the height of the billboard is x
we know, sinΘ = height/hypotenuse
⇒ sin30 = x/40
⇒ 1/2 = x/40
x = 20