We are given:
A right angled triangle with Perpendicular = 16 and base = 11
∠A = θ
Finding θ:
Using basic trigonometry, we know that Tanθ = Opposite / Adjacent
replacing the values for the angle θ
Tanθ = 11 / 16
[since 11 is the opposite side and 16 is the adjacent side to the angle]
θ = ArcTan(11/16)
θ = 34.5° OR 0.6 radians