interior angle

American  

noun

Geometry.

1. an angle formed between parallel lines by a third line that intersects them.

2. an angle formed within a polygon by two adjacent sides.

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interior angle British  

noun

1. an angle of a polygon contained between two adjacent sides

2. any of the four angles made by a transversal that lie inside the region between the two intersected lines

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interior angle Scientific  

/ ĭn-tîr′ē-ər /

1. Any of the four angles formed inside two straight lines when these lines are intersected by a third straight line.

2. An angle formed by two adjacent sides of a polygon and included within the polygon.

3. Compare exterior angle

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Etymology

Origin of interior angle

First recorded in 1750–60

Example Sentences

Each interior angle of a regular heptagon is a bit over 128 degrees, so when we put three of them together at a vertex, we get more than 360 degrees.

From Scientific American • Nov. 17, 2013

I got the first cut, but again, when I started cutting the interior angle, the bar worked its way out of the jig, and the tool dug in and broke.

From "October Sky" by Homer Hickam

A groove to the left of the group seems to show that this slab was at an interior angle of a building.

From A Catalogue of Sculpture in the Department of Greek and Roman Antiquities, British Museum, Volume I (of 2) by Smith, A. H.

This quatrefoil joins the interior angle ones of Zephaniah.

From Our Fathers Have Told Us Part I. The Bible of Amiens by Ruskin, John

The narrow entrance is at the exterior angle of the L, between the water-battery and the lighthouse; and in the interior angle are the Castelli, Konak, &c.

From The Atlantic Monthly, Volume 20, No. 121, November, 1867 by Various