Question

The diameters of the ends of a frustum of a cone are32cm and 20 cm. If its slant height is 10cm. Find the lateral surf

Answer 1

Complete Question:

The diameters of the ends of a frustum of a cone are 32 cm and 20 cm. If its slant height is 10 cm, find the lateral surface area of the frustum.

Given:

Diameters: D = 32 cm, d = 20 cm

l = 10 cm

To find:

Lateral surface area

Solution:

Lateral surface area of a frustum = $\tt{\pi (R + r)l}$

R = D/2 = 16 cm

r = d/2 = 10 cm

Lateral surface area = $\tt{\pi (16 + 10)10}$

=> 3.14 × 26 × 10

=> 31.4 × 26

=> 816.4 sq cm

______________

Answer 2

Answer: The lateral surface area of frustum is 816.4 cm²

Step-by-step explanation:

Given: Diameters of the end of a frustum of a cone are 32 cm and 20 cm.

Slant height: 10 cm

To find: Lateral surface area

.°. Radius1 = r = 20/2 =10cm

Radius2 = R = 32/2 16cm

Slant height = L =10cm

Lateral surface area = π(R+r)L

= 3.14 × (16+10) × 10

= 3.14 × 26 × 10

= 816.4cm²

The lateral surface area of frustum is 816.4 cm².