8 The curves \(C _ { 1 }\) and \(C _ { 2 }\) have polar equations, for \(0 \leqslant \theta \leqslant \pi\), as follows:
$$\begin{aligned}
& C _ { 1 } : r = a
& C _ { 2 } : r = 2 a | \cos \theta |
\end{aligned}$$
where \(a\) is a positive constant. The curves intersect at the points \(P _ { 1 }\) and \(P _ { 2 }\).
- Find the polar coordinates of \(P _ { 1 }\) and \(P _ { 2 }\).
- In a single diagram, sketch \(C _ { 1 } , C _ { 2 }\) and their line of symmetry.
- The region \(R\) enclosed by \(C _ { 1 }\) and \(C _ { 2 }\) is bounded by the \(\operatorname { arcs } O P _ { 1 } , P _ { 1 } P _ { 2 }\) and \(P _ { 2 } O\), where \(O\) is the pole. Find the area of \(R\), giving your answer in exact form.