dimensions:

length(l): is the distance between to bodies in(si) this is measured in meters .we also use centimetres or kilometres.we used rulers,measuring tapes an so on when we are measuring length.
surface area(s): is the space pccupied by two dimensions.length and width. in(si)united we measured sourface area in square meters. and other very common united is squares centemeres.
volume(v)is the total space occupied bu a body. its often measured in litres even in the(si) is the cubic metre. the volume of liquids or solids can be measured using measuring cylindres. in the case of the regular geometric SHAPES.WE CAN use mathematical formulas. for example the volumen of a sphere with radios(r)