Question

A rectangular piece of paper 11cm × 4cm is folded without overlapping to make a cylinder of height 4cm. Find the volume of the cylinder.​

Answer 1

Given:-

• A rectangular piece of paper 11cm × 4cm is folded without overlapping to make a cylinder of height 4cm.

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To find:-

• Volume of the cylinder.

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Solution:-

• Length of the paper becomes the perimeter of the base of the cylinder and width becomes height.

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Let,

• Radius of the cylinder be r.
• Height of the cylinder be h.

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★Perimeter of the base of the cylinder = 2πr = 11

$\tt\longmapsto{2 \pi r = 11}$

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$\tt\longmapsto{2 \times \dfrac{22}{7} \times r = 11}$

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$\tt\longmapsto{\boxed{\green{r = \dfrac{7}{4} cm}}}$

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Therefore,

$\star{\boxed{\sf{\orange{Volume\: of\: the\: cylinder = \pi r^2h}}}}$

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$\tt\longmapsto{\dfrac{22}{7} \times \dfrac{7}{4} \times \dfrac{7}{4} \times 4cm^3}$

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$\tt\longmapsto{\boxed{\red{38.5\: cm^3}}}$

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Hence,

• the volume of the cylinder is 38.5 cm³.