(Hopefully)Very quick volume calculation question

[venomxx]

Iv been looking for a way to calculate the volume of a cyllender with one end radius "x" and the other end with a radius "y".

I know you can do it by considering both circles the base's of 2 cones that when taken away from one another should equal the volume of the cyllender I want. BUT i don't have the height of the cone.

All I have to work with is the radius of the top and bottom of the cyllender and the height of the cyllender...any suggestions? Iv been looking around for a formula or alternate method but i have only found symmetrical cyllender methods.

Sorry for my ignorance if this is a simple answer!

 

[micromass]

Hi venomxx!

Check out http://en.wikipedia.org/wiki/Frustum
This gives the formula

$$V=\frac{\pi h}{3}(R^2+r^2+Rr)$$

where h is the height of your truncated cone, and where R and r are the two radii.

Do you need to prove this formula too? In that case, it's easiest when you know some calculus...

 

[venomxx]

Cheers for the quick reply micromass! That formula is giving me exactly what I needed! Ill give it a shot deriving it myself:)