if the radius of a circle is decreased 10 % , what happens to the area ?
"area of square = pi * radius ^ 2 new radius = 0.9 * old radius so new area = ( 0.9 ) ^ 2 old area = > 0.81 of old area = > 81 % old area ans : b"
subtract(const_100, multiply(power(divide(10, const_100), const_2), const_100))