Question

3. A fez, the cap used by the Turks, is shaped like the

frustum of a cone (see Fig. 1324) If its radius on the
open side is 10 cm, radius at the upper base is
and its slant height is 15 cm, find the area of material
used for making it​

Answer 1

Given that,

The radius of the open side, r₁ = 10 cm

The radius of the upper base, r₂ = 4 cm

Slant height, l = 15 cm

To find,

The area of material used for making it.

Solution,

The area of material used for making it​ = CSA of the frustrum + Area of the circle portion of upper side

`A=\pi (r_1+r_2)l+\pi r_2^2\\\\A=\pi (10+4)* 15+\pi * 4^2\\\\A=709.99\ cm^2`

So,
`709.99\ cm^2` of the area of material is used for making it.