Question

The vessel has the shape of a frustum of a cone. The
circumference of the bases of the frustum are 10 pi cm and 40 pi
cm and the height is 30 cm. Find the capacity of the vessel in liter.

Answer 1

Answer:

Curved Surface area of a frustum of a cone =πl(r

1

+r

2

) where l is the slant height,

r

1

and r

1

are the radii of the lower and upper ends of a frustum of a cone.

Circumference of the lower circular base =2π r

1

=18

⇒r

1

=

π

9

cm

Circumference of the upper circular base =2π r

2

=6

⇒r

2

=

π

6

cm

Given, curved Surface area of the frustum of a cone =π×l×(

π

9

+

π

6

)=180

l=15 cm