How to find the values of the six trigonometric functions for 180?

I like to imagine a triangle in place of the negative x axis of the unit circle where the opposite side = 0, the adjacent is - 1 and the hypotenuse = 1.

so sin 180 = 0/1 = 0, cos 180 = - 1/1 = - 1 and tan 180 = - 0/-1 = 0.

Then the other ratios are csc is 1/0 = indeterminate, sec = 1/-1 = - 1 and cot is indeterminate.