Question.
Find the total surface area of a hemisphere of radius $10 \mathrm{~cm}$. [Use $\pi=3.14$ ]
Solution:
Radius (r) of hemisphere = 10 cm
Total surface area of hemisphere = CSA of hemisphere + Area of circular end of hemisphere
$=2 \pi r^{2}+\pi r^{2}$
$=3 \pi r^{2}$
$=\left[3 \times 3.14 \times(10)^{2}\right] \mathrm{cm}^{2}$
$=942 \mathrm{~cm}^{2}$
Therefore, the total surface area of such a hemisphere is $942 \mathrm{~cm}^{2}$.
Radius (r) of hemisphere = 10 cm
Total surface area of hemisphere = CSA of hemisphere + Area of circular end of hemisphere
$=2 \pi r^{2}+\pi r^{2}$
$=3 \pi r^{2}$
$=\left[3 \times 3.14 \times(10)^{2}\right] \mathrm{cm}^{2}$
$=942 \mathrm{~cm}^{2}$
Therefore, the total surface area of such a hemisphere is $942 \mathrm{~cm}^{2}$.