Final answer:
In mathematics, the unit commonly used to define the proportions of any individual figure is the unit scale, which compares the dimensions of an actual object to the dimensions of a scale drawing or model.
Step-by-step explanation:
In mathematics, the unit commonly used to define the proportions of any individual figure is the unit scale.
A unit scale is a ratio that compares the dimensions of an actual object to the dimensions of a scale drawing or model that represents the actual object. This ratio is written as a fraction, with one value representing the actual object's dimension and the other value representing the corresponding dimension on the scale drawing or model.
For example, a unit scale on a map may read 1 inch = 100 feet. In this case, the ratio would be written as 1 inch/100 ft.