Question

Find the total surface area and volume of a hemisphere of radius 21cm

Answer 1

Total surface area of Hemisphere = 3πr²

=> TSA if Hemisphere :

$3 \times \frac{22}{7} \times 21 \times 21 = 4158 \: {cm}^{2}$

And, Volume of Hemisphere :

$\frac{2}{3} \pi {r}^{3} = \frac{2}{3} \times \frac{22}{7} \times 21 \times 21 \times 21 = 19404 \: {cm}^{3}$

@ItsChampion ✌️

Answer 2

Solution:

Formulas to be used:

• Volume of hemisphere = 2/3 πr³
• Total Surface Area of hemisphere = 3πr²

According to the question, the radius of the hemisphere is 21 cm.

Substituting the values in the respective formulas we get:

→ Volume of hemisphere = 2/3 × 22/7 × 21 × 21 × 21

→ Volume of hemisphere = 2 × 22 × 21 × 21

→ Volume of hemisphere = 19,404 cm³

→ TSA of hemisphere = 3 × 22/7 × 21 × 21

→ TSA of hemisphere = 3 × 22 × 3 × 21

→ TSA of hemisphere = 4158 cm²

Hence the TSA of hemisphere is 4,158 cm² and the Volume of the hemisphere is 19,404 cm³.