(a)[3]
Give the area of the shaded region in terms of $r$ and $\theta$.
(b)[4]
Given that $r = 10$ and $\theta = 0.6$, determine the perimeter of the shaded region.
Mathematics 9709 · AS & A Level · Circular measure
Circular measure — practice question
From the diagram, $ABC$ is an isosceles triangle with $AB = BC = r$ cm, and angle $BAC = \theta$ radians. Point $D$ is located on $AC$, and $ABD$ is a sector of a circle with centre $A$.