## Trigonometry (11th Edition) Clone

180$^{\circ}$ between 2nd and 3rd quadrant.
1. It is the same case as in 115 exercise. 180$^{\circ}$ cannot be in either quadrant. 180$^{\circ}$+360$^{\circ}$= 540$^{\circ}$ 180$^{\circ}$-360$^{\circ}$=-180$^{\circ}$ Co-terminal angles always in the same quadrant as original angle.