In mathematics breadth is used to describe the distance from the right side to the left side of a shape. You may be thinking that the definition of breadth sounds an awful lot like the definition. The definition of length is how long something is or the amount of vertical space or time it takes up.
Generally length is measured in two types of different units.
Think of how you would describe the distance along a road. This length is measured as a linear distance. You may be thinking that the definition of breadth sounds an awful lot like the definition. It is usually the longer of two distances of an object the other being the width.