interior angle

noun

1
: the inner of the two angles formed where two sides of a polygon come together
2
: any of the four angles formed in the area between a pair of parallel lines when a third line cuts them

Illustration of interior angle

Illustration of interior angle
  • agh bgh ghd ghc interior angle sense 2

Examples of interior angle 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.
This is a recursive relationship: The interior angle sum for an n-gon is 180 degrees more than the interior angle sum for an (n − 1)-gon. Patrick Honner, Quanta Magazine, 22 Mar. 2024 With each interior angle measuring 108 degrees, three pentagons leave a gap and four begin to overlap. Marisa Sloan, Discover Magazine, 21 July 2021 The result: a round-rimmed pint with an interior angle designed to give your pour the perfect head and aroma every time. Joe Jackson, Outside Online, 28 Jan. 2015

Word History

First Known Use

1756, in the meaning defined at sense 1

Time Traveler
The first known use of interior angle was in 1756

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Cite this Entry

“Interior angle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/interior%20angle. Accessed 13 Sep. 2025.

Kids Definition

interior angle

noun
: any of the four angles formed in the area between a pair of lines when a third line cuts them
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