hypotenuse

noun

hy·​pot·​e·​nuse hī-ˈpä-tə-ˌnüs 

-ˌnyüz

variants or less commonly hypothenuse

hī-ˈpä-thə-ˌnüs 

-ˌnyüz

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

By way of analogy, in flat space, the hypotenuse of a right triangle is always a2 + b2 = c2. —Daniel Garisto, Quanta Magazine, 7 Nov. 2025

That is, the squares of the two shorter lengths add up to the square of the final, longer side (the hypotenuse). —Ari Daniel, NPR, 16 Sep. 2025

As a result, the Mars Triangle will become altered again, resembling a more of a right triangle configuration on March 10, with the hypotenuse formed by Mars and Castor and the right angle at Pollux. —Joe Rao, Space.com, 17 Feb. 2025

The vertical hypotenuse also goes straight through the arbor of the power reserve gauge. —Allen Farmelo, Robb Report, 24 Oct. 2024

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

Rhymes for hypotenuse

• accrues
• accuse
• aircrews
• amuse
• bamboos
• breakthroughs
• canoes
• cashews
• chartreuse
• confuse
• construes
• defuse

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