Question

1 Find the surface area of a sphere of radius 21 cm.

Answer 1

Answer :-

• Surface Area of sphere = 5544 cm²

Given :-

• Radius of sphere = 21 cm

To Find :-

• Surface Area of Sphere = ?

Explanation :-

As we know, Formulae of surface area of sphere is

$\underline { \boxed { \bf \implies Surface \: of \: sphere = 4 \pi r^2 }}$

Now Substituting the values,

$\rm \implies Surface \: of \: sphere = 4 \pi r^2$

$\rm \implies 4 \times \dfrac{22}{7} \times (21)^2 \; \; cm^2$

$\rm \implies 4 \times \dfrac{22}{7} \times 21 \times 21 \; \; cm^2$

$\rm \implies 4 \times 22 \times 3 \times 21 \; \; cm^2$

$\rm \implies 88 \times 63 \; \; cm^2$

$\underline { \boxed { \bf \implies 5544 \; \; cm^2 }}$

Hence, the surface area of sphere is 5544 cm²

@Agamsain