|cube||length (l), width (w), height (h)|
|cylinder||diameter of base (d), length of cylinder (I)|
|cone||diameter of base (d), length of cylinder (I)|
The displacement can is filled with water above a narrow spout and allowed to drain until the water is level with the bottom of the spout.
As the irregular object is lowered into the displacement can, the water level rises. All the displaced water comes out of the spout and is collected in a measuring cylinder.
The displaced water in the cylinder occupies the same amount of space as the object in the can, which means that their volumes are the same.