Question

if cicumfrence of circle decrease by50% then the area of cirle is decreased by

Answer 1

C = 2πr

Let us say that the circumference is 100 units

then the radius would be = 100/2π = 50/π

which means the area is = π r² = π (50/π)² = 2500/π

Now the circumference will be reduced by 50% = 50 units

then radius would be = 50/2π = 25/π

and the area is = π r² = π (25/π)² = 625/π

then the reduction in the area = (2500 – 625)/π = 1875/π

% reduction = 1875/π /2500/π × 100

= 1875/2500 × 100 = 75 %

Answer 2

Hope it helps you....