Question

the area of a circular playground is 22176 metres square find the cost of fencing in this ground @ 50 rs/m

Answer 1

Hello.............. ^_^

Here is your answer......

Given :-
area of a circular playground is 22176 m square

$area \: \: of \: \: playgroud = 22176 {m}^{2} \\ \\ = > \pi {r}^{2} = 22176 \\ \\ = > \frac{22}{7} \times {r}^{2} = 22176 \\ \\ = > {r}^{2} = 22176 \times \frac{7}{22} \\ \\ (22176 \div 22 = 1008) \\ \\ = > {r}^{2} = 1008 \times 7 \\ \\ = > {r}^{2} = 7056 \\ \\ = > r = \sqrt{7056} \\ \\ = > r = 84$

radius = 84m

$circumference \: \: of \: \: circular \: \: playground = 2\pi \: r \\ \\ = 2 \times \frac{22}{7} \times 84 \: \: m\\ \\ = \frac{2 \times 22 \times 84}{7} \: m \\ \\ = \frac{3696}{7} \: m \\ \\ = 528m$

cost of fencing 1 m = Rs.50
so,

the cost of fencing 528m
= 528 X 50
= Rs. 26400

Hope it helps......... ^_^

Answer 2

Area of playground = 22176 m²
⇒ πr² = 22176 m²
r² = 22176/22/7 = 22176*7/22 = 7056 m²
r = √7056 = 84 m

Circumference of circle = 2πr = 2*22/7*84 = 528 m
Cost per meter = 50 Rs
cost per 528 m = 528*50 = 26400 Rs
Cost of fencing in this ground = 26400 Rs