Question

Radius= 21 cm and Height= 5 cm find the curved surface, Area of the base , Whole surface​

Answer 1

Given :-

• radius of base of the cylinder = 21 cm
• height of the cylinder = 5 cm

To Find :-

• curved surface area of the cylinder ?
• and area of the base of the cylinder?

Solution :-

we know that,

$\boxed{ \orange{ \bold{C.S.A \: of \: cylinder = 2\pi rh}}}$

$\bold{ : \implies 2 \times \frac{22}{ \cancel7} \times \cancel{21} \times 5 } \\ \\ \bold{: \implies 2 \times 22 \times 3 \times 5 } \: \: \: \\ \\ \bold{: \implies 660 \: {cm}^{2} } \: \: \: \: \: \: \: \: \: \: \: \: \: \: \:$

so, curved surface area of the cylinder is 660 cm²

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and now,

$\boxed{ \bold{base \: area \: = \pi {r}^{2} }}$

$\bold{: \implies \frac{22}{ \cancel7} \times \cancel{21} \times 21 } \\ \\ \bold{: \implies22 \times 3 \times 21 } \: \: \: \\ \\ \bold{: \implies1386 \: {cm}^{2} } \: \: \: \: \: \: \:$

so, base area of the cylinder is 1386 cm²

Answer 2

Answer:

Given :-

radius of base of the cylinder = 21 cm

height of the cylinder = 5 cm

To Find :-

curved surface area of the cylinder ?

and area of the base of the cylinder?

Solution :-

⟹2×722×21×5:⟹2×22×3×5:⟹660cm2

so, curved surface area of the cylinder is 660 cm²

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⟹722×21×21:⟹22×3×21:⟹1386cm2

so, base area of the cylinder is 1386 cm²