commensurable

In mathematics, "commensurable" describes quantities that share a common measure or can be expressed as integer multiples of a unit. This concept was fundamental to early Greek geometry, particularly for the Pythagoreans, who believed all reality could be understood through whole numbers and their ratios.12

However, the discovery of "incommensurable" quantities, like the diagonal of a unit square (which is the square root of 2), challenged this view. These quantities cannot be expressed as a simple ratio of two integers, leading to the concept of irrational numbers. The term "commensurable" can also be used more broadly to mean corresponding in size, amount, or degree, with its antonym "incommensurable" referring to things that are unlike or disproportionate.213