Question

The area of a circular playground is 22176 square m.find the cost of fencing the ground at the rate rs.50 per m

Answer 1

heya!

the area of the ground is 22176

r *r *22/7 = 22176

r*r*22=155232

r*r = 155232/22

r*r = 7056

r = 84m

now circumference

=> 2*22/7 * r

=> 44/7 * 84

=> 528m

cost of fencing at rate of 50m

=> 528 *50

=> 26400 rs

:)

wlcm

Answer 2

$\bold{ Given: }$

• The area of a circular playground is 22176 m².

• the rate of fencing is rs.50 per m.

$\bold{To \: find \: out : }$

Find the cost of fencing?

$\bold{Formula \: used : }$

★ Circumference of circle = 2πr

★ Area of circle = πr²

$\bold{Solution : }$

Let radius of playground be r cm.

So, by given condition

$\pi { r}^{2} = 22176$

$: \implies \: {r}^{2} = \frac{22176}{22} \times 7$

$: \implies {r}^{2} = 1008 \times 7$

$: \implies \: {r}^{2} = 7056$

$: \implies \: r = \sqrt{7056}$

$: \implies \: r = 84 \: m$

So,

$\sf{Circumference = 2\pi \: r}$

$\rightarrow \: 2 \times \frac{ 22}{ \cancel7} \times \cancel{84 }$

$\rightarrow \: 44 \times 12$

$\rightarrow \: 528 \: m$

Hence, Cost of fencing = 50 × 528 = Rs. 26400