# It is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. How many square metres of the sheet are required for the same?

**Solution:**

We know that,

Diameter = 2 × radius

Let the radius and height of the cylinder be 'r' and 'h' respectively.

Height of the tank, h = 1 m

Radius of the tank, r = 140 cm / 2 = 70/100 m = 0.7 m

Total surface area of the closed cylindrical tank = 2 π r (r + h)

= 2 × 22/7 × 0.7 m × (0.7 m + 1 m)

= 4.4 m × 1.7 m

= 7.48 m²

7.48 m² of the sheet is required for making the cylindrical tank.

**Video Solution:**

## It is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. How many square metres of the sheet are required for the same?

### Class 9 Maths NCERT Solutions - Chapter 13 Exercise 13.2 Question 2:

**Summary:**

It is given that it is required to make a closed cylindrical tank of height 1 m and base diameter 140 cm from a metal sheet. We have found that 7.48 m² of the sheet is required for making the cylindrical tank