decagon

American  

[dek-uh-gon, -guhn] / ˈdɛk əˌgɒn, -gən /

noun

Geometry.

1. a polygon having ten angles and ten sides.

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decagon British  

/ dɪˈkæɡənəl, ˈdɛkəˌɡɒn /

noun

1. a polygon having ten sides

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decagon Scientific  

/ dĕk′ə-gŏn′ /

1. A polygon having ten sides.

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Other Word Forms

• decagonal adjective
• decagonally adverb

Etymology

Origin of decagon

From the Medieval Latin word decagōnum, dating back to 1565–75. See deca-, -gon

Explanation

A decagon is a closed shape with ten sides and ten angles. Your geometry teacher would also tell you that a decagon is a polygon. The word decagon comes from Greek roots, deka, or "ten," and gōnia, "angle or corner." Any ten-sided shape can be called a decagon, whether it's a street sign or the doodle you draw in your notebook during math class. Speaking of math class, in geometry you may learn that a "regular decagon" is one with sides that are all equal to each other and with internal angles that all measure 144 degrees.

Example Sentences

Most of the list came from the state eighth grade curriculum: barometer, decagon, perpendicular .

From "Schooled" by Gordon Korman

They are not circular, but form the sides of an irregular decagon.

From Dikes and Ditches Young America in Holland and Belguim by Optic, Oliver

The solution is required later on in the construction of a regular decagon.

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

To construct a regular pentagon, we find it convenient first to construct a regular decagon.

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

This, however, does not change the real nature of his solution, nor does his solution become simpler by not mentioning the decagon.

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