Theory:

Hemisphere:
A one half of a sphere is called a hemisphere.
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Curved surface area:
C. S. A. \(=\) \(\frac{\text{Surface area of a sphere}}{2}\)
 
\(=\) 4πr22
 
\(=\) 2πr2
Curved surface area of a hemisphere \(=\) 2πr2 sq. units.
Total surface area:
T. S. A. \(=\) Curved surface area of a hemisphere \(+\) Area of the top region
 
\(=\) 2πr2 \(+\) \(\pi r^2\)
 
\(=\) \(3 \pi r^2\)
Total surface area of a hemisphere \(=\) \(3 \pi r^2\) sq. units.
Important!
The properties of a hemisphere are the same as the properties of a sphere.