Other forms: pentagons
A pentagon is a flat shape with five straight sides. A regular pentagon has five equal sides and five equal angles.
Unlike hexagons, pentagons will not tile a flat surface without gaps, which is why honeycombs are hexagonal and why the discovery of new pentagon tilings is a real event in mathematics. A football is made of pentagons and hexagons together. With a capital P, the Pentagon is the headquarters of the American defence department, named for its five-sided building, and it is used as shorthand for the American military itself.
1nounpentagonA flat shape with five straight sides.
“Draw a pentagon and join every corner to every other one.”
2nounheadquartersThe headquarters of the US defence department.
“The Pentagon declined to comment.”
pentagon is a shape.
Greek pente, five, plus gonia, an angle — a five-angle. The whole family counts corners: triangle, pentagon, hexagon, octagon, and once you know gonia means corner the names stop needing to be memorised.
Latin
pentagōnum
Middle French
pentagone
English, today
pentagon
Built from
From Middle French pentagone, from Latin pentagōnum. From Middle French pentagone, from Latin pentagōnum, from Ancient Greek πεντάγωνον, noun use of the neuter of the adjective πεντάγωνος (“five-angled”), from πέντε (“five”) + -γωνος (“angled”). Equivalent to penta + gon.
Etymology from Wiktionary, CC BY-SA
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