Question

3. A fez, the cap used by the Turks, is shaped like the
frustum of a cone (see Fig. 13.24). If its radius on the
open side is 10 cm, radius at the upper base is 4 cm
and its slant height is 15 cm, find the area of material
used for making it.​

Answer 1

Answer:

The area of material used to make Fez cap is-

4972/7.

Answer 2

$\bold{Given : }$

• Radius, r1 = 4 cm

• Radius, r2 = 10 cm

• Slant height, l = 15 cm

$\bold{To \: find \: out : }$

Find the area of material used for making it.

$\bold{Solution : }$

We know that,

Curved surface area = π ( r1 + r2 ) × l

$\rightarrow \: \frac{22}{7} (4 + 10) \times 15$

$\rightarrow \: \frac{22 \times 14 \times 15}{7}$

$\rightarrow \: 44 \times 15$

$\rightarrow \: 660 {cm}^{2}$

★Area of the top of the cap = πr²

= 22/7 × 16 = 352/7

= 50*2/7 cm²

Thus, total area of the material used for making the cap

= 660 + 50* 2/7

= 710*2/7 cm²

Hence, the area of material used for making the cap is 710*2/7.