Question

Find the curved surface area and total surface area of cylinder whose radius is 7cm and height 9cm. Take π = 22/7​

Answer 1

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Answer 2

Question:

Find the curved surface area and total surface area of cylinder whose radius is 7cm and height 9cm. Take π = 22/7

Solution:

${\underline {\underline {\boxed {\bf {\red { Given: }}}}}}$

• $\sf { r \: ( radius ) \: = 7cm }$

• $\sf { h \: ( height ) \: = 9cm }$

${\underline {\underline {\boxed {\bf {\red { To \: find: }}}}}}$

• $\sf { CSA \: of \: the \: cylinder }$

• $\sf { TSA \: of \: the \: cylinder }$

${\underline {\underline {\boxed {\bf {\red { Calculation: }}}}}}$

We know,

$\sf\red { CSA\: of \: the\: cylinder =( 2πrh)sq \: units}$

Substituting values-

$\sf { : \implies CSA\: of \: the\: cylinder = (2\times \dfrac{22}{7} \times 7 \times 9){cm}^{2}}$

$\sf { : \implies CSA \: of \: the\: cylinder = (2 \times \dfrac{22}{\cancel7} \times \cancel 7 \times 9){cm}^{2}}$

$\sf { : \implies CSA \: of \: the\: cylinder = (2 \times 22 \times 9 ){cm}^{2}}$

$\sf { : \implies CSA\: of \: the\: cylinder = (44 \times 9 ){cm}^{2}}$

$\sf { : \implies CSA\: of \: the\: cylinder = 396{cm}^{2}}$

Now,

We know,

$\sf\red { TSA\: of \: the\: cylinder = 2πr(r+h)sq units}$

Substituting values-

$\sf { :\implies TSA\: of \: the\: cylinder = 2 \times \dfrac{22}{7} \times 7 (7+9){cm}^{2} }$

$\sf { :\implies TSA\: of \: the\: cylinder = 2\times \dfrac{22}{\cancel7} \times \cancel7 (7+9){cm}^{2}}$

$\sf { :\implies TSA\: of \: the\: cylinder = (2\times 22 \times 16 ){cm}^{2}}$

$\sf { :\implies TSA\: of \: the\: cylinder = (44 \times 16 ){cm}^{2}}$

$\sf { :\implies TSA\: of \: the\: cylinder = 704{cm}^{2}}$

${\underline {\underline {\boxed {\bf {\red { Required \: Answers: }}}}}}$

$\dag \sf { CSA \: of \: the \: cylinder = {396cm}^{2}}$

$\dag \sf { TSA \: of \: the \: cylinder = {704cm}^{2}}$

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