Question

(i) A circular pond of diameter $28m$ is surrounded by a path $7m$ wide. Find the area of the path.
(ii) Find the area of a $2m$-wide circular path surrounding a circular plot of radius $20m$.

Answer 1

$\left(i\right)$ Area of the path $=\pi (R^2-r^2)$

Here,

$R=\frac{28}{2}+7=14+7=21m$

$r=21-7=14m$

Area of the path $=\pi ({21}^2-{14}^2)$

$=\frac{22}{7}\times 245$

$=770m^2$

$\left(ii\right)$ Area of circular path $=\pi (R^2-r^2)$

Here,

$R=20+2=22$

$r=22-2=20m$

Area of circular path $=\pi ({22}^2-{20}^2)$

$=\frac{22}{7}\times 84$

$=264m^2$