Question

Find the surface area of a sphere of radius $10.5\mathrm{cm}$. Assume $\mathrm{\pi }=\frac{22}{7}$

Answer 1

Find surface area of sphere

Given, radius of sphere, $r=10.5\mathrm{cm}$

Surface area ($S$) of a sphere is given as,

$S=4{\mathrm{\pi r}}^2$

Thus,

$$\begin{gathered} S=4·\frac{22}{7}·10.5^2 \\ =1386{\mathrm{cm}}^2 \end{gathered}$$

Therefore, surface area of the sphere of radius $10.5\mathrm{cm}$ is $1386{\mathrm{cm}}^2$