If the solid is a regular shape, such as a cylinder or sphere, you can find the appropriate dimensions and use formulas to find the result. If it is of a irregular size, I doubt if there is another method (even if there is, displacement of water would most likely be the simplest method)
The water displacement method is typically used to find the volume of an irregular solid. The object is submerged in a known amount of water, and the increase in water volume is measured. This increase in volume is equal to the volume of the irregular solid.
Liquid volume (displacement) and Solid volume (length x width x height)
There is no formula for finding the volume of an irregular solid. One method is water displacement which works as follows: Fill a graduated container with water and read off the volume of water. Then you submerge the irregular shaped solid in the water and measure the volume inside the container again. The difference between the two levels is the volume of the solid. This clearly cannot work for solids that are soluble in water. Other fluids may have to be used in such cases. Also, it will not work if the solid floats on water, but in that case you can submerge it using additional weights (whose volume you have measured).
Water Displacement technique
Liquid displacement
When you are trying to find the volume of an irregularly shaped object.
Water displacement
Traditionally, displacement is when you place a solid in a known amount of liquid, then determine the volume based on how much liquid is displaced by the object. You can't displace a liquid with another liquid and find its volume. With that said, the statement "One method used to determine the volume of solids and liquids is displacement" must be completely true. However, as we established in the previous paragraph, displacement is not a method for finding the volume of a liquid. Because an "and" operator is used in the statement, that means displacement must apply to both solids and liquids, or the statement as a whole is unsound. And since we previously determined that displacement is not a method for finding the volume of a liquid, this makes the statement unsound and false.
The water displacement method is typically used to find the volume of an irregular solid. The object is submerged in a known amount of water, and the increase in water volume is measured. This increase in volume is equal to the volume of the irregular solid.
Liquid volume (displacement) and Solid volume (length x width x height)
There is no formula for finding the volume of an irregular solid. One method is water displacement which works as follows: Fill a graduated container with water and read off the volume of water. Then you submerge the irregular shaped solid in the water and measure the volume inside the container again. The difference between the two levels is the volume of the solid. This clearly cannot work for solids that are soluble in water. Other fluids may have to be used in such cases. Also, it will not work if the solid floats on water, but in that case you can submerge it using additional weights (whose volume you have measured).
you multiply the length times width times height and you should get the volume. If the solid is of uneven shape, immerse it in the known volume of water and note the increase in volume of water due to inclusion of solid. This extra volume of water created by displacement is the volume of that solid.
if it is a solid, use the water displacement method.
Water Displacement technique
Liquid displacement
with a scale
Volume is difficult to calculate mathematically in a complex shape. Immersing an object in a liquid pushes out a volume of that liquid equal to the volume of the object. The result is called displacement because the solid displaces the liquid.