Q2.What is the ratio of volumes of the two cylinders formed by rolling a sheet of dimensions lxb in two different ways? Q3.What is the height of a right circular cylinder made from a rectangular sheet of length 20cm and breadth 15cm if it’s rolled along its length? Q4.What is the curved surface area of a cylinder obtained by rolling a square along its 7cm long side? Q5.What is the ratio of the total surface area and the curved surface area of the cylinder?

2. b : l

3. 20cm

4. 49

5.

Step-by-step explanation:

Solution 2:

Let cylinder is rolled along 'l':

Height of cylinder , h = length of rectangle = l

Perimeter of base = b

Let 'r' be the radius of cylinder's base:

Volume of a cylinder is given as:

Putting the values:

Let cylinder is rolled along 'b':

Height of cylinder , h = length of rectangle = b

Perimeter of base = l

Let 'r' be the radius of cylinder's base:

Volume of a cylinder is given as:

Putting the values:

Taking ratio:

Solution 3:

Rectangle is rolled along its length to make a cylinder, so height will be equal to its length.

height of cylinder = 20 cm

Solution 4:

Side of square = 7 cm

Height of cylinder =Side of square = 7 cm

7 cm will be the circumference of the circle.

i.e. = 7 cm

Curved surface area of a cylinder:

Putting the above values:

CSA = 7 7 = 49

Solution 5:

As calculated in above step:

CSA = 7 7 = 49

Total surface area =

Calculating value of r:

= 7 cm

Total surface area =

Ratio of TSA: CSA is

answer: 20

step-by-step explanation:

use formula for the circle a=3.14

step-by-step explanation: