Question

The area of a circular playground is $22176m^2$. Find the cost of fencing this ground at the rate of Rs 50 per m.

Answer 1

Given, area of circular playground $=22176m^2$

$\therefore \pi r^2=22176[\because areaofcircle=\pi r^2]$

$\Rightarrow \frac{22}{7}{r}^2=22176\Rightarrow r^2=1008\times 7$

$\Rightarrow r^2=7056\Rightarrow r=84m$

$\therefore$ Circumference of a circle $=2\pi r=2\times \frac{22}{7}\times 84$

$=44\times 12=528m$

$\therefore$ Cost of fencing this ground $=528\times 50=Rs.26400$