Question

The volume of the hemisphere is 2425 1/2 cubic centimetre. Find its curved surface area.​

Answer 1

Given:

• The volume of the hemisphere is 2425 1/2 cubic centimetre.

To find:

• Its curved surface area.

Solution:

• Shape is hemisphere,

Where,

• Volume = 2425.05cm³

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« Now, Finding radius of hemisphere,

→ Volume = (2/3)πr³

→ (2/3) × 22/7 × r³ = 2425.05

→ (2/3) × 22/7 × r³ = 4851/2

→ r³ = 4851 × 3 × 7/2 × 2 × 22

→ r³ = 4851 × 21/4 × 22

→ r³ = 441 × 21/4 × 2

→ r³ = 9261/8

→ r³ = 1157.625

→ r = 10.5cm

∴ Hence, Radius of the hemisphere is 10.5cm.

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« Now, Let's find CSA of the hemisphere,

→ CSA = 2πr²

→ 2 × 22/7 × (10.5)²

→ 2 × 22/7 × 110.25

→ 2 × 22 × 15.75

→ 44 × 15.75

→ 693cm².

∴ Hence, CSA of the hemisphere is 693cm².