Question

Find the radius of sphere whose surface area is $154c{m}^2$.

Answer 1

Let $r$ be the radius of the sphere.

Then according to the problem we've,

$\pi r^2=154$

or, $\frac{22}{7}\times r^2=154$

or, $r^2=7^2$

or, $r=7$.

So radius of the sphere is $7$ cm.