Start chapters home Start History history History expand_more
{{ item.displayTitle }}
No history yet!
Progress & Statistics equalizer Progress expand_more
Expand menu menu_open Minimize
{{ filterOption.label }}
{{ item.displayTitle }}
{{ item.subject.displayTitle }}
No results
{{ searchError }}
menu_open home
{{ courseTrack.displayTitle }}
{{ statistics.percent }}% Sign in to view progress
{{ }} {{ }}
search Use offline Tools apps
Login account_circle menu_open




In mathematics, a proportion is an equation showing the equivalence of two ratios, or fractions, with different numerators and denominators. The first and last numbers in the proportion are called the extremes, while the other two numbers are called the means. In a proportion, the product of the is equal to the product of the

As an example of proportionality, consider slices of pizza. Depending on the number of times it has been sliced, the same amount of pizza could be cut into or pieces.
Divide pizza


In this case, one-third of a pizza is the same amount of pizza as two-sixths or four-twelfths. If the simplified forms of two fractions are equal, then they are said to be proportional.

One-third is proportional to two-sixths and four-twelfths.


Geometric Proportionality

The concept of proportionality is also useful in geometric concepts such as the Triangle Proportionality Theorem or when determining if two figures are similar.

These two rectangles are proportional, or similar, because the ratio between their corresponding measures is constant. Some geometric figures, such as circles, spheres, squares, and cubes are always proportional to each other in size.