Jambmaths question:
Calculate the perimeter of a sector a circle of radius 9cm and angle 36o
Option A:
18
Option B:
$(18+\tfrac{9\pi }{5})cm$
Option C:
$(9+\tfrac{9\pi }{5})cm$
Option D:
$\tfrac{9\pi }{5}cm$
Jamb Maths Solution:
$\begin{align} & P=\frac{\theta }{360}\times 2\pi r+2r\text{ (perimeter of a sector)} \\ & P=\frac{{{36}^{\circ }}}{{{360}^{\circ }}}\times 2\pi \times 9+2\times 9 \\ & P=\left( \frac{9\pi }{5}+18 \right)cm \\\end{align}$
Jamb Maths Topic:
Year of Exam: