How do you find the volume of a three-dimensional irregular shape? - Answers

If it is a small shape that is denser than a convenient fluid and insoluble in it and also does not react with it then the displacement method is simplest. Fill a graduated cylinder with the fluid, measure the volume of the fluid. Then gently insert the shape and measure the apparent volume of the fluid. The difference between the two volume readings is the volume of the shape. If the shape is less dense than the fluid you have to make one change. You need to find a dense insoluble object. Measure the volume of the fluid with the dense object immersed in it. Then measure the volume when the dense object and the shape are joined together and submerged. The difference between the two measures is the volume of the shape. This method will not work with soluble shapes unless you can find a fluid that it is not soluble in. Similarly, you cannot use a fluid that will react. So measuring the volume of a lump of sugar or a lump of sodium using water are non-starters. Finally, the method will not work if the irregular shape is huge.