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

See Examples For:

exterior angle

It is said that he discovered the proposition relating to the exterior angle of a triangle.

From The Teaching of Geometry by David Eugene Smith

Let the tourist get admission at least into the garden and fling himself on that soft sward just opposite to the exterior angle of the house.

From Barchester Towers by Anthony Trollope

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 Sidney Heath

ABC is an exterior angle or angle of the polygon.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 6 "Foraminifera" to "Fox, Edward" by Various

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