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

The cutting is in the interior angle and is so made that the orthostate could be set at this place on a horizontal surface which ran inward.

From Problems in Periclean Buildings by Elderkin, G. W. (George Wicker)

At the left of this figure is a groove, suggesting that this was an interior angle stone.—Xanthos.

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

June.—Opposite, joining the interior angle ones of Haggai.

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