On the unit circle, the point P(-5/13, 12/13) lies on the terminal arm of an angle in standard position?
The angle is
(assuming that is what the question intended to ask).
In standard position with the unit length terminal arm at
which, in turn, implies
which can be solved using a calculator to obtain the result above.
I have no one sentence answer. See below.
If the question was to find the values of the six trigonometric functions, use the definition. Note that
(The point P is on the unit circle.)
Call the angle