Find how much space the object takes up by multiplying the height and base for the rectangular box, and multiplying the height and area of circle (area of circle formula--2πr) for the cylinder.
When we talk about volume we talk about three dimensional object which Occupies Space.Unit of Volume is Litre or Mililitre or Cm³,mm³.
So, Volume of Rectangular box means a three dimensional , six faced object called Cuboid which can keep any substance in it tha is Occupies Space and has mass.
As well as volume' of cylindrical container has same meaning .It has mass as well as it occupies Space can keep object or material inside it.
