Question

The radius of sphere is r cm. It is divided into two equal parts. Find the whole surface of two parts.

Answer 1

Given, the radius of the sphere $=rcm$.

If the sphere is divided into two equal parts, then the resulting parts are hemispheres with radius $=rcm$.

Therefore, the total surface area of each hemisphere$=3\pi r^{2}c{m}^2$

Then, the total surface area of both hemisphere $=2\times 3\pi r^2$
$=6\pi r^{2}c{m}^2$