Please explain how to find the angle

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

in the attachment.   i didn't see your choices.   the word which means there is choices.

step-by-step explanation:

(x,y)

x tells you how much left or right you go from the origin

y tells you how much down or up you go from the origin

so for example (-3,2), you go left 3 and up twice. i denoted which of the ordered pairs is which in my graph.