Question

A toy is made up of a hemisphere mounted on a cube.
The base block is a cube of side 3 cm and the hemisphere has a diameter of 2 cm.
Find the total surface area of the toy.​

Answer 1

Solution :

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The diameter of the hemisphere is 2 cm .

Thus , the radius is 1 cm .

The cube has a side length of 3 cm .

Total surface area of the cube :

> 6 a²

> 6 × 9

> 54 cm².

Let us subtract the area of overlap on the upper side of the cube -

> 54 - π r²

> 54 - π

CSA of hemisphere :

> 2 π r²

> 2 π

Total TSA of solid :

> 54 - π + 2π cm² .

> 54 + π cm²

≈ 57.14 cm² approximately .

This is the required answer.

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Answer 2

Answer:

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Solution :-

At first Radius of Hemisphere

Radius = 2/2 = 1 cm

Finding TSA of cube

TSA = 6a²

TSA = 6(3)²

TSA = 6(9)

TSA = 54 cm²

Now,

54 - π r²

54 - π

CSA of the Hemisphere

CSA = 2π

Now,

Finding TSA

TSA = 54 - π + 2π

TSA = 54 (2π - π)

TSA = 54 × π

TSA = 54 × 22/7

TSA ≈ 57.14 cm²