There is not really a rule to figuring out this question.There are kinda multiple ways to determine the volume of a 3D object. It really depends on what 3D object you are trying to find the volume for. But i can give you and example. Say you have a 3 dementional cube and you need to find the volume of that cube. You would take the bottom square of the cube and fine the area like you would any other square. But since this is a cube you have height to worrie about. So you will take the area you got for the bottom square and times that by the height. You will then have your answer. And if you are dealing with a cylinder same thing goes except with circle. Find the area of the bottom circle then times that by the area. Hope this helped sorry for taking so long.
