Question

what is the volume in m^3 of the biggest possible cylindrical pipe formed by folding the sheet as shown in the figure

Answer 1

Answer:

Here, the height is h=20 cm and the radius is r=7 cm, therefore,

V=πr

2

h=

7

22

×(7)

2

×20=

7

22

×49×20=3080 cm

3

Hence, the volume of the cylinder is 3080 cm

3

Explanation:

Answer 2

Given :   the sheet  8 m * 5  m

To Find : volume (in m³) of the biggest possible cylindrical pipe formed by folding the sheet

Solution:

the sheet  8 m * 5  m

Two possible fold

Case 1 : 8 is  circumference and 5 is height

Case 2 :  5 is  circumference and 8 is height

Case 1 : 8 is  circumference and 5 is height

2πR = 8

=> R =  4/π

Volume = πR²h

= π ( 4/π)² * 5

=  80/π  m³

Case 2 :  5 is  circumference and 8 is height

2πR = 5

=> R =  5/2π

Volume = πR²h

= π ( 5/2π)² * 8

=50/π  m³

80/π  > 50/π

Hence  volume (in m³) of the biggest possible cylindrical pipe formed by folding the sheet = 80/π