Question

From an angle of depression of 61 degrees, John

watches his friend approach his building while standing
on the rooftop. The rooftop is 17 m from the ground,
and John's eye level is at about 2m from the ground.
What is the distance between John's friend and the
building?
10.6
34.3
5.5
10.5

Answer 1

10.53

Explanation:

Given :

Height of building = 17m

John's eye level = 2 m

Total height (including eye level) = 17+2 = 19m

Angle of depression, θ = 61°

Let distance between John's friend and building = d

Using trigonometry :

Tan θ = opposite / Adjacent

Tan 61° = 19 / d

1.8040477 = 19 / d

d = 19 / 1.8040477

d = 10.53