Question

when a child folds a rectangular piece of paper into four. it is 20 cm in circumference. then what is the circumference of the whole paper folded?​

Answer 1

Answer:

A rectangular piece of paper 11cm*4cm is folded without overlapping to make an cylinder of height 4cm .find the volume of the cylinder?

Given that,

Length of the rectangiular paper= 11cm

Breadth of the rectangular paper= 4cm

Circumfernce of circular part of cyclinder = 2∏r

also given that cyclinder is rolled along its length

HenceCircumfernce of circular part of cyclinder =Length of the rectangiular paper

2∏r =11cm

2 X 22 / 7 X r = 11

44 / 7 X r = 11

r = 7 / 4 cm

Height of cylinder =Breadth of the rectangular paper = h =4cm

Volume of cyclinder =∏r2h

=22 / 7 x (7/4)2X 4

= 38.5cm3

Answer 2

Step-by-step explanation:

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

⇒2×722×r=11

∴r=47cm

 Now h=4cm

Volume of the cylinder (V)=πr2h

=722×47×47×4cm3

=38.5cm3