Question

Find the surface area of given sphere
i)10.5 cm
ii)5.6 cm
iii)14cm

Answer 1

${\LARGE{\sf{Question(i)}}}$

${\large{\sf{Radius\:10.5cm}}}$

${\huge{\underline{\color{green}{\rm{Answer}}}}}$

${\large{\sf{(i)1386cm^2}}}$

${\large{\sf{(ii)394.24cm^2}}}$

${\large{\sf{(i)2464cm^2}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

${\large{\underline{\underline{\sf{To\:Find}}}}}$

${\large{\sf{Area\:of\:sphere}}}$

${\large{\underline{\color{orange}{\sf{Given}}}}}$

${\large{\sf{Radius=10.5cm}}}$

${\large{\underline{\underline{\sf{Formula\:Using}}}}}$

${\large{\underline{\boxed{\color{red}{\sf{SA=4 \pi r^2}}}}}}$

${\large{\underline{\sf{Here}}}}$

${\large{\sf{SA=Surface\:Area}}}$

${\large{\sf{\pi=\frac{22}{7}}}}$

${\large{\sf{r=radius}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\qquad{\qquad{\qquad{\large{\underline{\underline{\color{blue}{\sf{Solution}}}}}}}}}$

${\qquad{\qquad{\quad{\large{\boxed{\sf{SA=4 \pi r^2}}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times (10.5)^2}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times 110.25}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 110.25}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 110.25}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{1}\times 15.75}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{Note \longmapsto 7\:is\:canceled\:by\:110.25\:resulting\:15.75}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{88 \times 15.75}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{1386}}}}}}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\large{\underline{\boxed{\color{green}{\sf{\longrightarrow Surface\:Area\:of\:sphere\:having\:radius\:10.5cm\:is\:1386cm^2}}}}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

${\large{\underline{\underline{\sf{Question\:(ii)}}}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\qquad{\qquad{\qquad{\large{\underline{\underline{\color{blue}{\sf{Solution}}}}}}}}}$

${\qquad{\qquad{\quad{\large{\boxed{\sf{SA=4 \pi r^2}}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times (5.6)^2}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times 31.36}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 31.36}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 31.36}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{1}\times 4.48}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{Note \longmapsto 7\:is\:canceled\:by\:31.36\:resulting\:4.48}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{88 \times 4.48}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{394.24}}}}}}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\large{\underline{\boxed{\color{green}{\sf{\longrightarrow Surface\:Area\:of\:sphere\:having\:radius\:5.6cm\:is\:394.24cm^2}}}}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

${\large{\underline{\underline{\sf{Question\:(iii)}}}}}$

${\large{\underline{\sf{Here}}}}$

${\large{\sf{SA=Surface\:Area}}}$

${\large{\sf{\pi=\frac{22}{7}}}}$

${\large{\sf{r=radius}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\qquad{\qquad{\qquad{\large{\underline{\underline{\color{blue}{\sf{Solution}}}}}}}}}$

${\qquad{\qquad{\quad{\large{\boxed{\sf{SA=4 \pi r^2}}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times (14)^2}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{4\times \frac{22}{7}\times 196}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 196}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{7}\times 196}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{\frac{88}{1}\times 28}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{Note \longmapsto 7\:is\:canceled\:by\:196\:resulting\:28}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{88 \times 28}}}}}}$

${\qquad{\qquad{\quad{\large{\sf{2464}}}}}}$

$\begin{gathered} \\ \qquad{\rule{150pt}{1pt}} \end{gathered}$

${\large{\underline{\boxed{\color{green}{\sf{\longrightarrow Surface\:Area\:of\:sphere\:having\:radius\:14\:is\:2464cm^2}}}}}}$

$\begin{gathered} \\ {\underline{\rule{200pt}{3pt}}} \end{gathered}$

${\qquad{\qquad{\qquad{\qquad{\qquad{\qquad{\scriptsize{\sf{@BrainlyResearcher}}}}}}}}}$

Answer 2

Answer:

Surface area of a sphere is 4πr2

where 'r' is the radius of the sphere and \[′π′\] is equal to 22/7 or 3.14.

In this case, we are given that the radius of the sphere is 10.5cm.

r=10.5cm.

Therefore, the surface of the sphere with radius 10.5cm is 1386 square centimeter.