exterior angle

American  

noun

Geometry.

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

2. an angle formed outside a polygon by one side and an extension of an adjacent side; the supplement of an interior angle of the polygon.

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exterior angle British  

noun

1. an angle of a polygon contained between one side extended and the adjacent side

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

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exterior angle Scientific  

/ ĭk-stîr′ē-ər /

1. The angle formed between a side of a polygon and an extended adjacent side.

2. Compare interior angle

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Etymology

Origin of exterior angle

First recorded in 1885–90

Example Sentences

The earliest windows of this period are long and narrow, with acutely pointed heads, the exterior angle being merely chamfered and the interior widely splayed.

From Our Homeland Churches and How to Study Them by Heath, Sidney

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

The proposition relating to the exterior angle was recognized by Pappus of Alexandria.

From The Teaching of Geometry by Smith, David Eugene

For the lines will form a triangle, and one of the alternate angles will be an exterior angle to the triangle, the other interior and opposite to it.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various

The angle formed by B, E is called an exterior angle; and that formed by E, F is an interior angle.

From Carpentry for Boys In a Simple Language, Including Chapters on Drawing, Laying Out Work, Designing and Architecture With 250 Original Illustrations by Zerbe, James Slough