Find the curved surface area,total surface area and volume of a hemisphere of diameter $42\, cm$.

(N/A) Given: Diameter $d = 42\, cm$,so radius $r = \frac{42}{2} = 21\, cm$.
$1$. Curved Surface Area $(CSA)$ of a hemisphere $= 2\pi r^2$
$= 2 \times \frac{22}{7} \times 21 \times 21 = 2 \times 22 \times 3 \times 21 = 2772\, cm^2$.
$2$. Total Surface Area $(TSA)$ of a hemisphere $= 3\pi r^2$
$= 3 \times \frac{22}{7} \times 21 \times 21 = 3 \times 22 \times 3 \times 21 = 4158\, cm^2$.
$3$. Volume of a hemisphere $= \frac{2}{3}\pi r^3$
$= \frac{2}{3} \times \frac{22}{7} \times 21 \times 21 \times 21 = 2 \times 22 \times 21 \times 21 = 19404\, cm^3$.