Illustration of hypotenuse
- ac hypotenuse
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
Example Sentences
Recent Examples on the Web For both before and after, the supposed hypotenuse (the longest side) of the right triangle is not a straight line. 
Mark Wolfmeyer, Popular Mechanics, 25 May 2022 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 In Figure 2, the length of line segment OP is 1, and OQ, the hypotenuse of the triangle, is 3.5. Quanta Magazine, 25 Aug. 2021 See More
Mark Wolfmeyer, Popular Mechanics, 25 May 2022 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 Witness file storage, which are fitted inside the unit one evening just as the building is closing, with great effort and much fighting, owing to the hypotenuse problem, which is often forgotten. Rafil Kroll-zaidi, Harper’s Magazine , 7 Dec. 2021 In Figure 2, the length of line segment OP is 1, and OQ, the hypotenuse of the triangle, is 3.5. Quanta Magazine, 25 Aug. 2021 See More 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-ˈpä-tə-ˌnüs
-ˌnyüz
: the side of a right triangle that is opposite the right angle