Question

Find (1) The CSA and (ii) The TSA of the hemisphere of radius 21 cm​

Answer 1

$\huge \sf \underline \orange{solution}$

The curved surface area of a hemisphere of radius 21 cm would be

$\sf{ \implies2\pi {r}^{2} } = \: 2 \times \frac{22}{7} \times 21 \times 21 \: {cm}^{2} \\ \\ {\sf \huge\boxed {\orange {\underline{2772 {cm}^{2}} }}}$

(2) the total surface area of the hemisphere would be

$\rm3\pi {r}^{2} = 3 \times \frac{22}{7} \times 21 \times 21 {cm}^{2} \\ \\ = \huge{ \sf {\green{ \underline {\boxed{4158 {cm}^{2} }}}}}$

Answer 2

Answer:

1.4πr2=4×722×21×21cm2=2772cm2

\begin{lgathered}\sf{2. \: \: 3\pi {r}^{2} = 3 \times \frac{22}{7} \times 21 \times 21 {cm}^{2} } \\ \\ = \sf{ \boxed{4158 {cm}^{2}}}\end{lgathered}2.3πr2=3×722×21×21cm2=4158cm2