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

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

So, of the area of material is used for making it.