Question

Find the total surface area of a hemisphere with diameter

42cm​

Answer 1

Answer:

The diameter of the hemisphere = 42 cm.

The radius of the hemisphere = 21 cm.

Formula of TSA of hemisphere = 3πr².

Hence, 3 × 22/7 × 21 × 21

Simplifying, 66 × 3 × 21

So, 4,158 cm².

Hence, The total surface area of the hemisphere = 4,158 cm².

$\rule{200}2$

• TSA of sphere = 4πr².
• CSA of hemisphere = 2πr².
• TSA of hemisphere = 3πr².
• Volume of sphere = 4/3 πr³.
• Volume of hemisphere = 2/3 πr³.

$\rule{200}2$

Answer 2

$\mathtt{\huge{ \fbox{Solution :)}}}$

Given ,

• The diameter of hemisphere = 42 cm
• Then , the radius of hemisphere = 42/2 cm i.e 21 cm

We know that , the total surface area of hemisphere is given by

$\large \mathtt{ \fbox{TSA \: of \: hemisphere = 3\pi {(r)}^{2} }}$

Thus ,

TSA = 3 × (22/7) × 21 × 21

TSA = 66 × 3 × 21

TSA = 66 × 63

TSA = 4158 cm²

Hence , the TSA of hemisphere is 4158 cm²

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