Question

a park is in the form of a rectangle 120m×100m.At the centre of the park there is a circularlawn.The area of park excluding lawn is 8700square metres .Find the radius of the circular lawn

Answer 1

Area of circular lawn = 120×100 - 8700 = 3300
Let r be the radius of circular lawn.
$\pi \times {r}^{2} = 3300 \\ {r}^{2} = 1050 \\ r = 32.4 \: m$