Question

find the surface area of a sphere having radius equal to 21 cm

Answer 1

Given that,

Radius of sphere is 21 cm

To find,

Surface area of sphere

Solution,

The formula of the surface area of a cube is given by :

$A=4\pi r^2$

r is radius of sphere

Put r = 21 cm in above formula, so

$A=4\times \dfrac{22}{7}\times (21)^2\\\\A=5544\ cm^2$

So, the surface area of the sphere is $5544\ cm^2$.

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