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

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

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

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

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