Let θ be an angle such that P is the terminal point of θ:
Some of the points Q,S,R,T can be the terminal point of θ/2.
Not sure what θ/2 looks like, any advice?
The angle θ goes anti-clockwise from the positive x-axis around to the red line. The angle θ/2 would go half-way (again in an anti-clockwise direction) from the positive x-axis towards the red line. It would therefore get to point Q.
Thank you! That makes sense
Edit: I also noticed that point S is also a terminal point of θ/2