Question

4) What is the total surface area of a hemisphere of radius r?
(a) 4nr
(b) ar?
(c) 2nr?
(d) 3nr?
mcqs​

Answer 1

Step-by-step explanation:

The surface area of a sphere of radius r is 4πr ^2 . Half of this is 2πr ^2 .

If you have a hemispherical object then it has a base which is a circle of radius r.

The area of a circle of radius r is πr ^2

and thus if the hemisphere is meant to include the base then the surface area is 2πr ^2 +πr ^2 =3πr ^2 .