Question

The height of cylinder is 21cms and the radius of its base is 5cms. Find its curved surface area.​

Answer 1

Step-by-step explanation:

The radius of the base of a right circular cylinder is 5 cm and height is 21 cm.

Here, r=5 cm and h=21 cm.

Curved surface area of cylinder =2πrh

2 * 22/7 * 5 * 21

44 * 15

= 660 cm²

∴ The curved surface area of cylinder is 660 cm²

Answer 2

Given:

• Height of cylinder is 21cm
• Radius of base of cylinder is 5cm

To find:

• Curved surface area(CSA) of cylinder?

Solution:

We are given that height of a cylinder is 21cm and radius of its base is 5cm.

Now, to find Curved surface area, we know that :

$\huge{\boxed{\large{\sf{\green{Curved\:surface\:area_{(cylinder)}\:=\: 2πrh}}}}}$

Where,

• π = $\dfrac{22}{7}$
• r = radius of cylinder
• h = height of cylinder

Put all known values in it :

$\large{\sf{Curved\:surface\:area_{(cylinder)}\:=\: 2πrh}}$

$\large{\implies{\sf{Curved\: surface\:area_{(cylinder)}\:=\: 2×\dfrac{22}{7}×5×21}}}$

$\large{\implies{\sf{Curved\: surface\:area_{(cylinder)}\:=\: 2×\dfrac{22}{\cancel{7}}×5×\cancel{21}}}}$

$\large{\implies{\sf{Curved\: surface\:area_{(cylinder)}\:=\: 2×22×5×3}}}$

$\large{\implies{\sf{Curved\: surface\:area_{(cylinder)}\:=\: 660}}}$

Therefore,

$\large{\boxed{\sf{\pink{Curved\: surface ~area~ of~ cylinder~is~660cm²}}}}$