11.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{dc0ac5df-24a7-41b5-8410-f0e9b332ba64-30_738_837_242_614}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{figure}
Circle \(C _ { 1 }\) has equation \(x ^ { 2 } + y ^ { 2 } = 100\)
Circle \(C _ { 2 }\) has equation \(( x - 15 ) ^ { 2 } + y ^ { 2 } = 40\)
The circles meet at points \(A\) and \(B\) as shown in Figure 3.
- Show that angle \(A O B = 0.635\) radians to 3 significant figures, where \(O\) is the origin.
The region shown shaded in Figure 3 is bounded by \(C _ { 1 }\) and \(C _ { 2 }\)
- Find the perimeter of the shaded region, giving your answer to one decimal place.