(i)[1]
Express angle $CAO$ in radians as a multiple of $\pi$.
(ii)[4]
Find the area of the shaded region, giving your answer in terms of $r$, $\pi$ and $\sqrt{3}$ in simplest form.
Mathematics 9709 · AS & A Level · Circular measure
Circular measure — practice question
In the diagram, $ACB$ is a semicircle with centre $O$ and radius $r$, and arc $OC$ belongs to a circle centred at $A$.