Question

the radius of a solid hemisphere is $2r$. Find its surface area.

Answer 1

We have,

Radius of a solid hemisphere $=2r$

We know that the surface area of the hemisphere $=2\pi R^2$

Let $S$ be the required surface area

$S=2\pi (2r{)}^2$

$=2\pi \times 4r^2$

$=8\pi r^2$