Let P, Q, R, and S be the terminal points on the circle below, and let theta be an angle such that P is the terminal point of theta. 
Order the points P, Q, R, and S so that the first point is the terminal point for -theta , the second point is the terminal point for theta-pi, the third point is the terminal point for theta-pi/2 and the fourth point is the terminal point for theta+4pi.
