Question

A circular flowerbed is surrounded by a path $1m$ wide. The diameter of the flowerbed is $40m$. Find the area of the path. ($\pi =\frac{22}{7}$)

• A. $128.86m^2$
• B. $130m^2$
• C. $135.1m^2$

Answer 1

The correct option is A $128.86m^2$


Given: Diameter of flowerbed $=40m$, width of path $=1m$

In order to find the area of the flowerbed which is circular in shape, we need to find the area of the outer circle and then subtract the area of the inner circle.

Radius of inner circle $=20m$

Radius of outer circle $=20+1=21m$

Area of a circle $=\pi r^2$

Area of outer circle $=\pi r^2$

$=\frac{22}{7}\times 21\times 21$

$=22\times 21\times 3$

$=22\times 63=1386m^2$

Area of inner circle $=\pi r^2$

$=\frac{22}{7}\times 20\times 20$

$=\frac{22\times 20\times 20}{7}$

$=\frac{8800}{7}=1257.14m^2$

Area of path $=1386-1257.14=128.86m^2$