# A tent is in the shape of a cylinder surmounted by a conical top. If the height and diameter of the cylindrical part are 2.1 m and 4 m respectively, and the slant height of the top is 2.8 m, find the area of the canvas used for making the tent. Also, find the cost of the canvas of the tent at the rate of ₹ 500 per m^{2}. (Note that the base of the tent will not be covered with canvas)

**Solution:**

The figure of the tent below can be created as per the given information

From the above figure, it can be seen that the diameter of the cylindrical part is equal to the diameter of the conical part as the cylindrical part is surmounted by the conical part.

As it's given that the base of the tent will not be covered by the canvas then the base of the cylindrical part of the tent is not included to get the area of the canvas required.

The surface of the tent includes the curved surface of the cylindrical part and the curved surface of the conical part only.

The area of the canvas used for making the tent is the surface area of the tent.

Area of the canvas used = CSA of the cylindrical part + CSA of the conical part

We will find the area of the canvas by using formulae;

CSA of the cone = πrl, where r and l are the radius and slant height of the cone respectively.

CSA of the cylinder = 2πrh, where r and h are the radius and height of the cylinder respectively.

Cost of the canvas of the tent = Area of the canvas × Rate of the canvas

Height of the cylinder, h = 2.1 m

Diameter of the cylinder, d = 4 m

Radius of the cylinder, r = d/2 = 4/2 m = 2m

Radius of the cone, r = 2 m

Slant height of the cone, l = 2.8 m

Area of the canvas used = CSA of the cylindrical part + CSA of the conical part

= 2πrh + πrl

= πr (2h + l)

= 22/7 × 2 m × (2 × 2.1 m + 2.8 m)

= 44/7 m × 7 m

= 44 m^{2}

Cost of the canvas of the tent = Area of the canvas × Rate of the canvas

= 44 m^{2} × ₹ 500/m^{2}

= ₹ 22000

Thus, the area of the canvas used for making the cylindrical tent is 44 m^{2} and the cost of the canvas is ₹ 22000.

**Video Solution:**

## A tent is in the shape of a cylinder surmounted by a conical top. If the height and diameter of the cylindrical part are 2.1 m and 4 m respectively, and the slant height of the top is 2.8 m, find the area of the canvas used for making the tent. Also, find the cost of the canvas of the tent at the rate of ₹ 500 per m^{2}. (Note that the base of the tent will not be covered with canvas)

### NCERT Solutions Class 10 Maths - Chapter 13 Exercise 13.1 Question 7 :

The area of the canvas used for making the cylindrical tent surrounded by a conical top and the cost of the canvas of the tent are 44 m^{2} and ₹ 22000 respectively.