Question

The internal surface area of a hollow hemisphere is 77 cm2 and its external surface area is 308 cm2. What is the thickness of the hollow hemisphere?​

Answer 1

Answer:

Step-by-step explanation:

Inner surface area (ISA)=77cm.sq

2πr×r=ISA

r×r=(77×7)÷(2×22)

=539÷44

=12.25

r=√12.25

=3.5

OSA=308=2πR×R

R×R =(308×7)÷(2×22)

=2156÷44

=49

R=√49

=7

Thickness=R-r

=7-3.5

=3.5cm