A)$\alpha+\beta=180^{\circ}$
B)$\beta-\alpha=200^{\circ}$
C)$\beta=4\alpha+40^{\circ}$
D)$\beta=5\alpha-20^{\circ}$
I solved it by taking $$\cos x=1-2\sin^232^{\circ}$$
Therefore $x=64$
So the two values of $x$ can be $64$ and $334$, so B) should be the right answer, but the answer is actually c. Where am I going wrong?
Note that: $$\cos x=\cos 64^\circ \Rightarrow x=\pm64^\circ+ 360^\circ n \\ n=0 \Rightarrow x=64^\circ\\ n=1 \Rightarrow x=-64^\circ +360^\circ =296^\circ $$