Question

the surface area of sphere is 616sqm the surface area of its hemisphere​

Answer 1

Answer:

surface area of a sphere is 616

4*pie*r^2=616

4*(22/7)*r^2=616

r^2=49

r=7

Hope it helps~

Answer 2

Answer:

$308 \: {cm}^{2}$

Step-by-step explanation:

$\huge \color{red} \boxed{\color{blue}⁽⁽◝( •Given :-• )◜⁾⁾}$

$: \implies \: CSA \: of \: sphere = 616 \: {cm}^{2}$

$\huge \color{blue} \boxed{\color{cyan}⁽⁽◝( • To \: find:-• )◜⁾⁾}$

$: \implies \: CSA \: of \: hemisphere$

Using the given conditions,

$: \implies \: CSA \: of \: sphere = 616 \: {cm}^{2}$

$\: \: \: \: \: \: \: \: \: \: \: : \implies \: 4\pi {r}^{2} = 616$

$\: \: \: \: \: \: \: \: \: \: \: : \implies4 \times \frac{22}{7} \times {r}^{2} = 616$

$\: \: \: \: \: \: \: \: \: \: \: \: : \implies {r}^{2} = \frac{616 \times 7}{4 \times 22}$

$\: \: \: \: \: \: \: \: \: \: \: \: \: : \implies \: {r}^{2} = 49$

$\: \: \: \: \: \: \: \: \: \: \: \: : \implies \: r = 7 \: cm$

According to the question,

$: \implies \: CSA \: of \: hemisphere = 2\pi {r}^{2}$

$\: \: \: \: \: \: \: \: \: \: \: : \implies2 \times \frac{22}{7} \times 7 \times 7$

$\: \: \: \: \: \: \: \: \: \: \: : \implies \: 308 \: {cm}^{2}$

Hence area of hemisphere is

$308 \: {cm}^{2}$

Alternate method,

Given:-

CSA of sphere = $616 \: {cm}^{2}$

We know that,

CSA of hemisphere = $\frac{1}{2} \times$CSA of sphere

$CSA \: of \: hemisphere =$

$\: \: \: \: \: \: \: \: \: \: \: : \implies \: \frac{1}{2} \times 616$

$\: \: \: \: \: \: \: \: \: \: \: : \implies 308 \: {cm}^{2}$