Question

Buglass.
The slant height of a frustum of a cone is 4 om and
the perimeters (circumference) of its circular ends
are 18 cm and 6 cm. Find the curved surface area of
the frustum cone and volume​

Answer 1

Answer:

We know that Curved surface area of frustum = ( 1+ 2) Here l = 4 cm We need to find r1 & r2 Now, Curv.

Answer 2

Given,

Slant height of frustum of cone (l) = 4 cm

Let ratio of the top and bottom circles be r1 and r2

And given perimeters of its circular ends as 18 cm and 6 cm

⟹ 2πr1 = 18 cm; 2πr2 = 6 cm

⟹ πr1= 9 cm and πr2 = 3 cm

We know that,

Curved surface area of frustum of a cone = π(r1 + r2)l

= (πr1+πr2)l = (9 + 3) × 4

 = (12) × 4 = 48 cm2 .

Therefore, the curved surface area of the frustum = 48 cm2 .