Question

find CSA of solid hemisphere if the TSA solid hemisphere is 12 pi cmsq​

Answer 1

Given:

• TSA of solid hemisphere = 12π cm²

To find:

• CSA of the hemisphere

Method:

TSA of solid hemisphere = 3π r²

We already know that the value of TSA is 12π cm²

12 π = 3π r²

Dividing by π on both sides,

12 = 3r²

⇒r² = 12 ÷ 3

⇒r² = 4

⇒r = ±2

⇒r = +2 or -2

Side cannot be negative. So radius = 2cm

Now let us find out CSA of the hemisphere.

CSA of solid hemisphere = 2 π r²

⇒CSA = 2 × π × 2²

⇒CSA = 8 π cm²

∴ CSA of the hemisphere = 8π cm²