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

From The Teaching of Geometry by Smith, David Eugene

At each exterior angle of the imperfect polygon was a column with a cubiform capital.

From Two Summers in Guyenne by Barker, Edward Harrison

If one side of a triangle be produced, the exterior angle shall be greater than either of the interior opposite angles.

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

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

From Barchester Towers by Trollope, Anthony

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