Question

A lamp shade is in form of a frustum of a cone , its upper and lower diameter are 10cm and 20cm respectively , its height is 12cm . Calculate the volume of the frustum

Answer 1

V = 8796.45
`cm^3`

Explanation:

Given data :

A lamp shade is in the form of a frustum of a cone.

The upper diameter of the cone, r = 10 cm

The lower diameter of the cone, R = 20 cm

The height of the frustum, h = 12 cm

Therefore, the volume of the frustum of cone is given by :

`V = (1)/(3) \pi H ( R^2 + Rr+r^2)`

Putting the values, we get

`V = (1)/(3) \pi * 12 [( 20)^2 + (20)(10)+(10)^2]`

`$V=4 \pi[400 + 200+100]$`

`$V=4 \pi[700]$`

V = 8796.45
`cm^3`

Thus the volume of the frustum of cone is V = 8796.45
`cm^3`