Question

a square piece of paper of side 12cm is rolled to form a cylinder.find the curved surface area of the cylinder

Answer 1

Answer:

Step-by-step explanation:

circumference of the base circle = 2 x pi x r =12cm

height of the cylinder = 12 cm

 C.S.A of a cylinder = 2 x pi x r x h

                              = (2 x pi x r) x h

                              =12 x 12

                              = 144 sq

Answer 2

Given:

A square piece of paper of the side 12cm is rolled to form a cylinder.

To find:

The curved surface area of the cylinder.

Solution:

As we know that the curved surface area of a cylinder having radius 'r' and height 'h' is given by:

$2\pi \: r \: h$

Now,

As given, we have,

The measure of the side of a square piece of paper = 12 cm

As it is rolled to form a cylinder, so,

Height of the cylinder = measure of the side of a square piece of paper = 12 cm

Also, in the given cylinder,

Circumference of the base circle of cylinder=

$2\pi \: r = \: side \: of \: square \:paper = 12cm$

So,

The curved surface area of the cylinder

$= 2\pi \: r \: h$

$= 12 \times 12$

$= 144 {cm}^{2}$

Hence, the curved surface area of the cylinder is 144 Square centimetres.