Question 832246
The curved surface area of a hemisphere is given by the formula
SA = 2*pi*r^2
The radius of the inner surface is 22/2 = 11, so
SA of inner surface = 2*pi*11^2 = 760.26542216872996370796 = 760.2654 square cm
The radius of the outer surface is 11 + 10 = 21
SA of the outer surface = 2*pi*21^2 = 2770.88472046619763632405 = 2770.8847 square cm