Question

on decreasing the radius of the circle by 30 % the area will increase by ?

Answer 1

Answer:

Area of a circle with radius r = πr2. Now if the radius decreases by 30%, radius becomes r − (30% of r) = r − 0.3r = 0.7r, which changes the area of circle to π(0.7r)2=(0.49)πr2.