The radius has to stay the same length so we can eliminate 12
- just changes the direction
To go negative, we add 180 or subtract 180
120+180 = 300
We could add 360 or subtract 360 and end up at the same point
120+360 = 480
120 - 360 =-240
(4,-240) is the same point
(-4,480) is in the opposite direction because of the negative sign
