A=pi*r2
So if the radius is increased by 20% (times 1.2) then
A = pi * (1.2*r)2
or
A= pi*1.44r2
so the area is increased by 44%
So if the radius is increased by 20% (times 1.2) then
A = pi * (1.2*r)2
or
A= pi*1.44r2
so the area is increased by 44%