Question

If surface area of a sphere is 676π cm², find it's radius.

Answer 1

area of sphere = 676 π cm
radius = ?
676π = 4πr×r
676 = 4 × r^2
676/4=r^2
169= r^2
√169= r^2
13 = r
radius is 13 cm

Answer 2

Given:

The surface area of a sphere is 676π cm².

To find:

The radius.

Solution:

The radius of a sphere is 13 cm.

To answer this question, we will follow the following steps:

First of all, we should know that in a sphere of radius 'r', the surface area is given by using the formula:

$= 4 \: \pi \: {r}^{2}$

Now,

As given,

We have,

The surface area of a sphere = 676π cm²

So,

$676\pi = 4\pi {r}^{2}$

On solving the above, we get,

$676 = 4 {r}^{2}$

$169 = {r}^{2}$

On taking square root on both sides, we get,

$r = 13 \: cm$

Hence, the radius of a sphere having a surface area of 676π cm² is 13 cm.