Question

5. A closed cylindrical tank of radius 7 m and height 3m is made from a sheet of metal.
How much sheet of metal is required
​

Answer 1

$\boxed{\boxed{\mathbf{440 m^2}}}$

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$\underline\text{We know that}$,

Area of Closed Cylinder = Curved Surface Area of Cylinder + 2(Area of Circle)

=> $\mathsf{2 \pi r h + 2(\pi r^2)}$

=> $\mathsf{2 \pi r (r + h)}$

$\textsf{Area of Closed Cylinder =}$ $\mathsf{2 \pi r h(r + h)}$

$\underline\text{Here}$,

$\mathsf{\pi = \frac{22}{7}}$

$\mathsf{Radius = 7m}$

$\mathsf{Height = 3m}$

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Substituting the values in the Formula, we get,

$\mathsf{2 \times \frac{22}{7} \times 7 (7 + 3)}$

$\mathsf{=> 2 \times 22 (10)}$

$\mathsf{=> 44 \times 10}$

=> $\boxed{\mathbf{ 440 cm^2}}$

Answer 2

Answer:

We know that

,

Area of Closed Cylinder = Curved Surface Area of Cylinder + 2(Area of Circle)

=> \mathsf{2 \pi r h + 2(\pi r^2)}2πrh+2(πr

2

)

=> \mathsf{2 \pi r (r + h)}2πr(r+h)

\textsf{Area of Closed Cylinder =}Area of Closed Cylinder = \mathsf{2 \pi r h(r + h)}2πrh(r+h)

\underline\text{Here}

Here

,

\mathsf{\pi = \frac{22}{7}}π=

7

22

\mathsf{Radius = 7m}Radius=7m

\mathsf{Height = 3m}Height=3m

_________________________________

Substituting the values in the Formula, we get,

\mathsf{2 \times \frac{22}{7} \times 7 (7 + 3)}2×

7

22

×7(7+3)

\mathsf{= > 2 \times 22 (10)}=>2×22(10)

\mathsf{= > 44 \times 10}=>44×10

=> \boxed{\mathbf{ 440 cm^2}}

440cm

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