Question

The area of a circular plot 39424m².calculate the cost of fencing the plot at the rate of ₹6 per metre.​

Answer 1

@nswer

let the radius is r .

now...

$\frac{22}{7} r {}^{2} = 39424 \\ = > r {}^{2} = 12544 \\ = > r = \sqrt{12544} \\ = > r = 112 \: \: m$

now the perimeter is

$= 2 \times \frac{22}{7} \times 112 \\ = 704 \: \: metre$

total cost at rate of RS6/m² is

$= (704 \times 6) \: \: rs \\ = 4224 \: \: rs$

Answer 2

Given

area of circular plot = 39424 m^2

πr^2 =39424m^2

r^2 = 39424m^2*7/22

r^2 = 12544m^2

r = 112 m

circumferance of circle = 2πr = (2*22*112m)/7=704m

so

cost of fencing = 704m*6= ₹4224