In the figure below $P$ and $Q$ are the centres of the circle and $PQ =9$. What is the area of the shaded region ?

Question

$\begin{array}{1 1} (a)\; 54 \pi - \frac{81 \sqrt{3}}{4} \\ (b)\; 54 \pi + \frac{81 \sqrt{3}}{4} \\ (c)\; 54 \pi - \frac{81\sqrt{3}}{2} \\ (d)\; 54 \pi + \frac{81 \sqrt{3}}{2}\end{array}$