Question

Find the volume of a cylinder that has a diameter of 7 and a height of 8.

28 Pi
392 Pi
448 Pi
98 Pi

Answer 1

We know , the volume of a cylinder is given by the formula – πr²h, where r is the radius of the cylinder and h is the height.

• Diameter - 7
• Height - 8
• radius = 7/2

Therefore, putting the values, we get,

`\Large \mathcal \purple {Volume }\large\red\implies \tt \large \:\pi \: {r}^(2)h`

`\Large \mathcal \purple {Volume }\large\red\implies \tt \large \:\pi * \: \bigg((7)/(2) \bigg)^(2) \: * \: 8 \\`

`\Large \mathcal \purple {Volume }\large\red\implies \tt \large \:\pi \: * \: (7)/(2) \: * \: (7)/(2) \: * \: 8 \\`

`\Large \mathcal \purple {Volume } \large\red\implies \tt \large \:\pi \: * \: (7)/(2) \: * \: (7)/( \cancel2) \: * \: \cancel{8} \: ^( \orange4) \\`

`\Large \mathcal \purple {Volume }\large\red\implies \tt \large \:\pi \: * \: (7)/( \cancel2) \: * \: {7} \: * \: \cancel4 \: ^( \orange2) \\`

`\\ \Large \mathcal \purple {Volume }\large\red\implies \tt \large \:\pi \: * \: 7 \: * \: 7 \: * \: 2`

`\Large \mathcal \purple {Volume }\ \large\red\implies \tt \large \:\pi \: * \: 49 \: * \: 2`

`\Large \mathcal \purple {Volume }\large\red\implies \tt \large \:98 \:\pi`

Hence , the volume of cylinder is 98 pi

Answer 2

Required solution :

• Diameter (d) = 7
• Height = 8

Therefore,

• Radius (r) = d / 2
• Radius (r) = 7/2

We know that :

• V = πr^2h

Substituting the values :

>> V = π × (7 / 2)^2 × 8

>> V = π × (49 / 4) × 8

>> V = π × 49 × 2

>> V = 98π

Henceforth,

• 98 pi is the answer.