heptagon
Americannoun
noun
Other Word Forms
Etymology
Origin of heptagon
First recorded in 1560–70, heptagon is from the Greek word heptágōnos seven-cornered. See hepta-, -gon
Explanation
A heptagon is a polygon with seven sides, just as an octagon has eight sides. With seven sides, a heptagon must be lucky. Triangles and rectangles are two of the most common polygons (enclosed shapes), but there are many more, including the heptagon, a seven-sided polygon. You don't see many of these in nature bigger than molecules, but people have found several uses for this seven-sided figure, most commonly in coins: the British 20p and 50p pieces are both heptagons. The roots are Greek, and this word shares the hept prefix with other seven-related words such as heptad, heptameter, and heptathlete.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
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
To give the 50-new-penny coin a distinctive appearance, the Decimal Currency Board designed what it proudly billed as the world's first coin in the shape of "an equilateral curve heptagon."
From Time Magazine Archive
Even before the wall-screen had died, Westfall's beam was trying to get through it, and when the visiray revealed the interior of the heptagon, the quiet and methodical physicist was shaken from his habitual calm.
From Spacehounds of IPC by E. E. (Edward Elmer) Smith
Both men stared at the heptagon, frankly puzzled; for the screens of the strange vessel did not radiate, nor did the material of the walls yield under the terrible force of the beam.
From Spacehounds of IPC by E. E. (Edward Elmer) Smith
His explanation, however, which is altogether geometrical, inasmuch as it depends on the properties of the heptagon, seems quite unsatisfactory, though Selden appears to have been inclined to adopt it.
From Notes and Queries, Number 69, February 22, 1851 A Medium of Inter-communication for Literary Men, Artists, Antiquaries, Genealogists, etc. by George Bell
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
