4.
\begin{figure}[h]
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\caption{Figure 1}
\includegraphics[alt={},max width=\textwidth]{e4d38009-aa70-4c55-9765-c54044ffaa31-2_554_561_1635_762}
\end{figure}
Fig. 1 shows the sector \(A O B\) of a circle, with centre \(O\) and radius 6.5 cm , and \(\angle A O B = 0.8\) radians.
- Calculate, in \(\mathrm { cm } ^ { 2 }\), the area of the sector \(A O B\).
- Show that the length of the chord \(A B\) is 5.06 cm , to 3 significant figures.
The segment \(R\), shaded in Fig. 1, is enclosed by the arc \(A B\) and the straight line \(A B\).
- Calculate, in cm , the perimeter of \(R\).