Question

If the radius of the hemisphere is $3r.$ Find its curved surface area.

Answer 1

The curved surface area of hemi-sphere $=2\pi (radius{)}^2$

Here, Radius $=3r$

Therefore, the curved surface area of the given hemisphere

$=2\pi (3r{)}^2=2\pi \times 9r^2=18\pi r^2$ square units