- The definition of the Pythagorean Theorem is a mathmatical relationship of the lengths of the sides in a right triangle - if you square the length of the two shorter sides and add them together, that will equal the length of the longest side squared.
An example of the Pythagorean Theorem is a 3 x 4 x 5 triangle - 3 squared is 9, 4 squared is 16, and 5 squared is 25. 9 plus 16 equals 25.

## Pythagorean theorem

Geom. the theorem that in a right triangle the hypotenuse squared is equal to the sum of the squares of the other sides (i.e., c=a+b)

## Pythagorean theorem

noun

The theorem that the sum of the squares of the lengths of the sides of a right triangle is equal to the square of the length of the hypotenuse.

**Pythagorean theorem**

The Pythagorean theorem is a2 + b2 = c2.

## Pythagorean theorem

Proper noun

- (geometry) A mathematical theorem which states that the square of the length of the hypotenuse of a right triangle is equal to the sum of the squares of those of the two other sides.
*The Pythagorean theorem only applies to right triangles.*

- (functional analysis) A generalization of the Pythagorean theorem for Euclidean triangles to Hilbert spaces

Origin

Named after Pythagoras, from Ancient Greek *Πυθαγόρας* (Pythagoras), Greek mathematician and philosopher who by tradition is credited with theorem’s discovery and proof.