Question

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

Answer 1

Let r be the radius of the circular playground.

Now, $\pi r^2=22176$

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

$\Rightarrow r^2=7056$

$\Rightarrow r=84cm$

Now, circumferenece $=2\pi r=2\times \frac{22}{7}\times 84=528m$

So, cost of fencing = Rs. 50 $\times$ 528 = Rs. 26400