Math Help - Finding the angle

1. Finding the angle

A circle with a radius of 1.
the point P giving the co-ordinates (-√3/2 , -1/2)

So it rotates through the 1st and 2nd quadrant and ends in the 3rd at point P. The angle in the third I'm unsure of. I know that its already 180 degrees.

would i solve the 3rd quadrant angle by finding it using cos θ A/H

so it would be (-√3/2)/1 = -1.225?

Thanks for any help.

2. $\displaystyle \theta = \frac{7\pi}{6}$

recommend you learn the unit circle ...

3. Hey thanks for your help, much appreciated.