2.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{f7994129-07ee-4f6d-9531-08a15a38b794-04_350_639_210_712}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{figure}
The shape \(A B C D O A\), as shown in Figure 1, consists of a sector \(C O D\) of a circle centre \(O\) joined to a sector \(A O B\) of a different circle, also centre \(O\).
Given that arc length \(C D = 3 \mathrm {~cm} , \angle C O D = 0.4\) radians and \(A O D\) is a straight line of length 12 cm ,
- find the length of \(O D\),
- find the area of the shaded sector \(A O B\).