What is the Derivation of formula of volume of cuboid?

Answer 1

In the case of a rectangular cuboid, I would say that the volume is simply DEFINED to be length x width x height. The volume of other, more complicated shapes, can then be derived, based on this basic definition. But you do need to have a starting point, i.e., "How is volume even defined in the first place?"Just to show that this definition makes sense, think of a rectangular cuboid as having integer values for length, width, and height. In that case, you can divide it into unit cubes (cubes of side length 1), and it is easy to see (basically, by counting the unit cubes) that the number of unit cubes will be length x width x height - IN THIS SPECIAL CASE.