Question

If area of the base of a cylinder is 11 sq cm and it's height is 7cm , then it's volume is??​

Answer 1

Solution:-

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★ Area of the base = 11cm²

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$\tt\longrightarrow{\pi r^2 = 11}$

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$\tt\longrightarrow{\dfrac{22}{7} r^2 = 11}$

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$\tt\longrightarrow{r^2 = \dfrac{7}{2}}$

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$\tt\longrightarrow{r = \sqrt{\dfrac{7}{2}}}$

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• Now, we have radius and height of the cylinder.

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★ Volume = πr²h

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$\tt\longrightarrow{Volume = \dfrac{22}{7} \times \bigg( \sqrt{\dfrac{7}{2}} \bigg)^2 \times 7}$

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$\tt\longrightarrow{Volume = 22 \times \dfrac{7}{2}}$

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$\tt\longrightarrow{Volume = 11 \times 7}$

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$\bf\longrightarrow{Volume = 77\: cm^3}$

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Alternate method

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★ Volume of a cylinder is the product of height and area of the base.

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• Therefore

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$\tt\longmapsto{Volume = 7 \times 11}$

$\bf\longmapsto{Volume = 77\: cm^3}$

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Hence,

• Volume of the cylinder is 77 cm³.

Answer 2

Given :-

→ Area of the base of a Cylinder = 11 cm²

→ Height of the Cylinder = 7 cm

To Find :-

→ Volume of that Cylinder

Solution :-

$\underline{\bf{\dag} \:\mathfrak{As\;we\;know\: that\: :}}$

$\star\: \boxed{\sf{\blue{ Area\;of\;base=\pi r^{2}}}}$

→ Let's find out the radius by putting the values in this formula !

$\sf \implies \pi r^{2} = 11$

$\sf \implies \dfrac{22}{7} \times r^{2} = 11$

$\sf \implies r^{2} = 11 \times \dfrac{7}{22}$

$\sf \implies r^{2} = \dfrac{7}{2}$

$\sf \implies r = \sqrt{\dfrac{7}{2}}$

→ Now ATQ we need to find it's volume

$\underline{\bf{\dag} \:\mathfrak{As\;we\;know\: that\: :}}$

$\star\: \boxed{\sf{\blue{Volume\;of\;Cylinder= Area\;of\;base \times Height }}}$

→ Let's solve by putting the values in this formula !

$\sf \implies 11 \times 7$

$\sf \implies 77\;cm^{3}$

∴ Volume of this cylinder is 77 cm³