Question

The area of a circular playground is 22176 m2 find the cost of fencingthis ground at the rs 50 per metre

Answer 1

ar=22176m²

     area of circle = π r²
 (22176 × 7)÷22= r²
                         r²=7056
                         r =84

circumference is the fence of the circle=2πr
                                                                  =2 × 22/7 × 84
                                                                  =528m
now, 
ATQ

COST ON TOTAL FENCING ON CIRCULAR field is 50/m² 
So,
50 × 528
rs.26400

Answer 2

area of ground=22176m2
$\pi \: r { }^{2} h$