Question

A rectangular piece of paper 11 cm × 8 cm is folded without overlapping to make a cylinder of height 8 cm. Find the volume of the cylinder.​

Answer 1

Given a Rectangular piece of paper 11cm×4cm is folded without overlapping to make a cylinder of height 4 cm

The length of the paper becomes the circumference of the base of the cylinder and width becomes height.

Let radius of the cylinder=r and height=h

Circumference of the base of cylinder =2πr=11cm

⇒2×

7

22

×r=11

∴r=

4

7

cm

Now h=4cm

Volume of the cylinder (V)=πr

2

h

=

7

22

×

4

7

×

4

7

×4cm

3

=38.5cm

3

Answer 2

Answer :

• Volume of cylinder = 77cm³

Given :

• A rectangular piece of paper 11cm × 8cm is folded without overlapping to make a cylinder of height 8cm

To find :

• Volume of cylinder

Solution :

Given,

• Length of rectangle = 11cm
• Breadth of rectangle = 8cm

Here, A rectangular piece of paper is folded without overlapping to make a cylinder so,

• Height of cylinder = breadth of rectangle (8cm)

• Let the radius of rectangle be r

A rectangular piece of paper is folded without overlapping to make a cylinder so,

• Perimeter of rectangle (bottom) = Length of the rectangle

Here,

• Circumference of circle is 11cm
• Height is 8cm

As we know that

• Circumference of circle = 2πr

We need to find the radius of cylinder

⇢ 2πr = 11

⇢ 2 × 22/7 × r = 11

⇢ 44/7 × r = 11

⇢ r = 11 × 7/44

⇢ r = 7/4

Hence , Radius is 7/4

Now, we need to find the volume of cylinder

As we know that,

• Volume of cylinder = πr²h

⇢ Volume of cylinder = πr²h

⇢ Volume of cylinder = 22/7 × (7/4)² × 8

⇢ Volume of cylinder = 22/7 × 7/4 × 7/4 × 8

⇢ Volume of cylinder = 77cm³

Hence , Volume of cylinder = 77cm³