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
As that dazzling wall sprang into being, the sparkling green protection died from the walls of the heptagon.
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
Such was the power of the Vorkulian vessels that in less than twenty hours another heptagon slowed to a halt beside the Sirius and two of its crew were wafted aboard.
From Spacehounds of IPC by E. E. (Edward Elmer) Smith
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