right triangle

noun

: a triangle having a right angle see triangle illustration

Examples of right triangle in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That is to say, each of their proofs demonstrates that the square of a right triangle’s longest side equals the sum of the squares of the two shorter sides. — Alexa Robles-Gil, Smithsonian Magazine, 30 Oct. 2024 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 Any Pythagorean triple — including 3, 4, and 5 — also gives the lengths of the three sides of a right triangle. — Ari Daniel, NPR, 16 Sep. 2025 Vega, Deneb and Altair make a right triangle with the right angle at Deneb, this is called the Summer Triangle. — Jesse Emspak, Space.com, 22 Aug. 2025 See All Example Sentences for right triangle

Word History

First Known Use

1675, in the meaning defined above

Time Traveler
The first known use of right triangle was in 1675

Rhymes for right triangle

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Browse Nearby Words

right-to-work
right triangle
(right) under someone's nose
See all Nearby Words

Cite this Entry

“Right triangle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/right%20triangle. Accessed 7 Jul. 2026.

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Kids Definition

right triangle

noun
: a triangle having a right angle

More from Merriam-Webster on right triangle

Britannica.com: Encyclopedia article about right triangle

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