Question

Please explain the logic behind it

Answer 1

first of all, you need to assume that this shape is like a cone. So cone has a height and you can find it by using Thales's theorem. so it would be

`(x)/(x + 6) = (4)/(8)`

x is 6. So the total height of the cone has founded.

To find the volume of this frustum we have to subtract the volume of the small cone(at the top of the frustum) which has 6 cm in height from the big cone with 12 cm in height.

big cone Volume: ⅓(8²π×12)

-

small cone Volume: ⅓(4²π × 6)

=

frustum volume : 224π