Question

Find total surface of a sphere whose radius is 21 cm .​

Answer 1

Answer:

The total surface area of the sphere is 5544 cm².

Step-by-step-explanation:

We have given that,

Radius of sphere ( r ) = 21 cm

We have to find the total surface area of sphere.

We know that,

$\displaystyle{\pink{\sf\:Surface\:area\:of\:sphere\:=\:4\:\pi\:r^2}}$

$\displaystyle{\implies\sf\:Surface\:area\:of\:sphere\:=\:4\:\times\:\dfrac{22}{7}\:\times\:(\:21\:)^2}$

$\displaystyle{\implies\sf\:Surface\:area\:of\:sphere\:=\:4\:\times\:\dfrac{22}{\cancel{7}}\:\times\:\cancel{21}\:\times\:21}$

$\displaystyle{\implies\sf\:Surface\:area\:of\:sphere\:=\:4\:\times\:22\:\times\:3\:\times\:21}$

$\displaystyle{\implies\sf\:Surface\:area\:of\:sphere\:=\:4\:\times\:3\:\times\:22\:\times\:21}$

$\displaystyle{\implies\sf\:Surface\:area\:of\:sphere\:=\:12\:\times\:462}$

$\displaystyle{\implies\underline{\boxed{\red{\sf\:Surface\:area\:of\:sphere\:=\:5544\:cm^2}}}}$

∴ The total surface area of the sphere is 5544 cm².

Answer 2

Answer:

by bias is lisa in blackpink and your