The surface area of a sphere is $616 {\text{cm}}^2$. Its radius is

Concept: A sphere is indeed a solid shape with a curved surface. The surface area of a sphere can be defined as the total area covered by its outer surface.

Here, the surface of a sphere $=616{ \mathrm{cm}}^2$

$\therefore 4\pi r^2=616$

$\Rightarrow 4\times \frac{22}{7}\times r^2=616$

$\Rightarrow r^2=\frac{616\times 7}{4\times 22}=49$

$\Rightarrow r=\sqrt{49}=7 \mathrm{cm}$

Hence, the radius of the sphere is $7 \mathrm{cm}$.