Question

How to evaluate trig functions that are not on the unit circle?

Answer 1

Don't be confused.
Trig functions are not on the trig unit circle. The variable arc x, with origin A and extremity M, rotates on the trig unit circle. The position of M on the circle create trig functions in terms of the arc AM = x.
There are 4 axis of the Trig circle that define the 4 main functions of x.
The horizontal axis OAx defines the function f(x) = cos x
The vertical axis OBy defines the function f(x) = sin x
The vertical ax At defines the function f(x) = tan x.
The vertical Bz defines the function f(x) = cot x.
Reminder.
Triangle trigonometry studies about angles and sides of a triangle.
General Trigonometry studies about the variation of the arc AM = x and its related trig functions.