Question

In the figure given, $O$ is the centre of the circle. What is the $\angle AOC$?

• A. ${160}^o$
• B. ${150}^o$
• C. ${120}^o$
• D. ${100}^o$

Answer 1

The correct option is D ${100}^o$

R.E.F image

angle subtended by chord is twice

at center as that of circumference

In $ABOC[{20}^{\circ }+{30}^{\circ }+\theta +(360-2\theta )={360}^{\circ }]$

$\Rightarrow \theta ={50}^{\circ }$ $\therefore \angle AOC={100}^{\circ }$