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\includegraphics[max width=\textwidth, alt={}, center]{e439eea6-76f0-41eb-aa91-bd0f3e4e1a07-3_438_805_849_669}
In the diagram, \(A B C\) is a semicircle, centre \(O\) and radius 9 cm . The line \(B D\) is perpendicular to the diameter \(A C\) and angle \(A O B = 2.4\) radians.
- Show that \(B D = 6.08 \mathrm {~cm}\), correct to 3 significant figures.
- Find the perimeter of the shaded region.
- Find the area of the shaded region.