Question

the diameter of a cylinder is 25 cm and height is 20 cm find the curved surface area​

Answer 1

Answer:

To solve this question firstly find the radius of the cylinder and we can find its curved surface area by applying the formula to find the curved surface area of the cylinder that is$CSA \: of \: cylinder=2 \pi rh$ Where r and h are the radius and height of the cylinder respectively.

Given that diameter of the cylinder is 25 cm.

diameter of the cylinder is 25 cm.So, radius of cylinder will be 25/2 cm.

Also, given that height of the cylinder is 20 cm .

As, we know that,

$CSA \: of \: cylinder=2 \pi rh$

So,

$CSA = 2 \times \frac{22}{7} \times \frac{25}{2} \times 20 \\ = \frac{11000}{7} \\ =1571.42{cm}^{2}$

Answer 2

$\large \underline{ \underline{ \sf \: Solution : \: \: \: }}$

Given ,

$\star$Diameter of cylinder = 25 cm

$\star$So , radius (r) = 25/2 i.e 12.5 cm

$\star$Height of cylinder (h) = 20 cm

We know that ,

$\large \fbox{ \fbox{ \sf \: CSA \: of \: cylinder = 2πrh \: \: }}$

$\implies \sf CSA = 2 \times \frac{22}{7} \times 12.5 \times 20 \\ \\ \implies \sf CSA = \frac{44}{7} \times \frac{125}{\cancel 10} \times \cancel 20 \\ \\\implies \sf CSA = \frac{44}{7} \times 125 \times 2 \\ \\\implies \sf CSA = \frac{11000}{7} \\ \\\implies \sf CSA = 1571.4 \: \: {cm}^{2}$

Therefore , the required curved surface area (CSA) of cylinder is 1571.4 cm²