Question

If the radius of a circle with centre o is increased by 7%, then the area is increased by

Answer 1

Initial radius=r
Final radius=r+(7÷100)r=1.07r

Area formula=π×r×r

initial area=π×r×r

final area=
=π×1.07r×1.07r
=π×r×r×1.1449

area increased by
(π×r×r×1.1449 - π×r×r)÷ (π×r×r)
=1.1449-1
=0.1449%