# hypotenuse

## noun

hy·​pot·​e·​nuse hī-ˈpä-tə-ˌnüs
-ˌnyüz
variants or less commonly hypothenuse
1
: the side of a right-angled triangle that is opposite the right angle
2
: the length of a hypotenuse

## Illustration of hypotenuse

• ac hypotenuse

## Examples of hypotenuse in a Sentence

Recent Examples on the Web Start with a trajectory that’s at a right angle to the hypotenuse (the long side of the triangle). Quanta Magazine, 15 Feb. 2024 In the second triangle, the unequal angles cause the fake hypotenuse to bend outside the true triangle’s hypotenuse. Mark Wolfmeyer, Popular Mechanics, 25 May 2022 Now measure the angle between the hypotenuse and the table. Leila Sloman, Scientific American, 10 Apr. 2023 In the first position, the unequal angles cause the fake hypotenuse to bend in from the true triangle. Mark Wolfmeyer, Popular Mechanics, 25 May 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'hypotenuse.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

## Word History

Etymology

earlier hypothenusa, hypothenuse, borrowed from Latin hypotēnūsa, borrowed from Greek hypoteínousa, noun derivative (with grammḗ "line" or pleurá "side" understood) from feminine of hypoteínōn, present participle of hypoteínein "to stretch under, put under, subtend," from hypo- hypo- + teínein "to stretch, extend" — more at tenant entry 1

Note: The nominal use of hypoteínousa in Greek is apparent in passages such as the following, from the Deipnosophistae of Athenaeus of Naucratis (10.13), where "line/lines" or "side/sides" are understood: "Apollódōros dè ho arithmētikòs kaì thûsaí phēsin autòn hekatómbēn epì tôi eurēkenai hóti trigṓnou orthogōníou [he] tḕn orthḕn gōnían hypoteínousa íson dýnatai taîs periechoúsais …." ("And Apollodorus the Calculator says that he [Pythagoras] even sacrificed a hecatomb when he discovered that in a right-angled triangle the [square of the] line subtending ("hypoteínousa") the right angle is equal to [the square of] the lines embracing it.)"

First Known Use

1594, in the meaning defined at sense 1

Time Traveler
The first known use of hypotenuse was in 1594

hypotenuse

## Cite this Entry

“Hypotenuse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hypotenuse. Accessed 9 Aug. 2024.

## Kids Definition

hypotenuse

noun
hy·​pot·​e·​nuse hī-ˈpät-ᵊn-ˌ(y)üs
-ˌ(y)üz
1
: the side opposite the right angle of a right triangle
2
: the length of a hypotenuse

## More from Merriam-Webster on hypotenuse

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