# rule of three

### noun Mathematics.

the method of finding the fourth term in a proportion when three terms are given.

## Words nearby rule of three

rule of eleven, rule of engagement, rule of law, rule of outlet, rule of the road, rule of three, rule of thumb, rule out, rule the roost, ruled surface, ruleless

## Origin of rule of three

First recorded in 1585–95

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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

## Examples from the Web for rule of three

## British Dictionary definitions for rule of three

rule of three

### noun

a mathematical rule asserting that the value of one unknown quantity in a proportion is found by multiplying the denominator of each ratio by the numerator of the other

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