Since $\angle ACB = \frac{1}{2}\angle AOB$ and $\angle AOB$ is a straight angle, $\angle ACB$ equals—

Question

Accepted Answer

$90^{\circ}$

Answer

$0^{\circ}$

Answer

$45^{\circ}$

Answer

$180^{\circ}$

Since ∠ACB=12∠AOB\angle ACB = \frac{1}{2}\angle AOB∠ACB=21​∠AOB and ∠AOB\angle AOB∠AOB is a straight angle, ∠ACB\angle ACB∠ACB equals—