waecmaths question:
A sector of a circle with radius 6cm subtends an angle of 60o at the centre. Calculate its perimeter in terms of π
Option A:
2(π +8)cm
Option B:
2(π +3)cm
Option C:
2(π +2)cm
Option D:
(π +12)cm
waecmaths solution:
$\begin{align} & r=6cm \\ & \theta ={{60}^{\circ }} \\ & Perimeter=2r+\left( \frac{\theta }{{{360}^{\circ }}}\times 2\pi r \right)=2\times 6+\left( \frac{60}{{{360}^{\circ }}}\times 2\pi \times 6cm \right) \\ & Perimeter=(12+2\pi )cm=2(6+\pi )cm \\\end{align}$
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