In the above figure, O is the centre of the circle.
If $\angle BCO=30 ^\circ$ and BC=$12 \sqrt 3$, what is the area of triangle ABO?
I worked like OA=OB=OC(radii of the circle).
So, $\angle OBC=30^\circ,\angle BOC=120^\circ$
$\angle AOB=60^\circ,\angle ABO=60^\circ,\angle OAB=60^\circ$
Triangle AOB comes to be an equilateral triangle.
How Do I find OA?