Find the area of canvas required for a conical tent of height 24 m and base radius 7 m.

#### Solution

The amount of canvas required to make a cone would be equal to the curved surface area of the cone.

The formula of the curved surface area of a cone with base radius ‘*r*’ and slant height ‘*l*’ is given as

Curved Surface Area = `pirl`

It is given that the vertical height ‘*h*’ = 24 m and base radius ‘*r*’ = 7 m.

To find the slant height ‘*l*’ we use the following relation

Slant height, *l* = `sqrt(r^2 + h^2)`

= ` sqrt(7^2 + 24^2)`

= `sqrt(49+576)`

= `sqrt(625)`

*l* = 25

Hence the slant height of the given cone is 25 m.

Now, substituting the values of *r* = 7 m and slant height *l* = 25 m and using ` pi 22/7` in the formula of C.S.A,

We get

Curved Surface Area = `((22).(7)(25))/7`

= (22) (25)

= 550

Therefore the Curved Surface Area of the cone is 550 m^{2 }.