- the theorem that the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides.
Origin of Pythagorean theorem
First recorded in 1905–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- A theorem stating that the square of the length of the hypotenuse of a right triangle is equal to the sum of the squares of the lengths of the other sides. It is mathematically stated as c2 = a2 + b2, where c is the length of the hypotenuse and a and b the lengths of the other two sides.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The theorem is often expressed a2 + b2 = c2.
The simplest whole number expression of this theorem is called the 3, 4, 5 triangle. In a right triangle, if one side measures three units, and the second side measures four units, the hypotenuse must measure five units because 32 + 42 = 52; that is, 9 + 16 = 25.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.