Hello, I'm in the process of creating a calculation spreadsheet with Excel. In this spreadsheet I need to calculate a volume of an object that has an arbitrary cross-section but from the side of the cross-section, it is always triangle. At the moment the spreadsheet calculates the volume of a circular or a rectangular cross-section. This I was able to achieve by integration. The cross-section can be created by giving the coordinates for the vertices. Does anyone have any ideas of a formula or equation, if you prefer, that could calculate the volume when the cross-section truly is arbitrary? PS. I tried to attach an image of the object that would've perhaps given you a better understanding of what I mean but if you do not see it, then that means the upload button is not working.