Question

if area of a semi circular field is 30800 sq.m. then the perimeter of the field is

Answer 1

Area of semi-circle = 1/2*πr²
30800 =1/2*22/7*r²
r² = 30800*2*7/22
r² =19600
r=√19600 = 140 m
Perimeter of semi-circle = πr+2r = 22/7*140+2*140 = 720 m

Answer 2

Solution: Area of semi circular =30800sq m
So, πr^2/2=30800
r^2=30800×2/π
r^2=30800× 2 ×7 /22
r^2= 30800×7/11
r^2=19600
r=140
Now, Perimeter of field= r(π+2)
= 140(22/7 + 2)
= 140(22+14/7)
=140× 36/7
= 20×36=720 m