What does dodecagonal mean?
Dodecagonal is a geometric adjective describing any flat shape that has twelve straight sides and twelve angles. Derived from the Greek roots 'dodeka', meaning twelve, and 'gonia', meaning angle, it is the adjective form of the noun 'dodecagon'. The word appears most often in mathematics and technical writing, but it also surfaces in descriptions of architecture, engineering, and everyday objects — the British fifty-pence piece, for example, is famously dodecagonal. A regular dodecagonal figure is one in which all twelve sides are of equal length and all interior angles are equal, each measuring 150 degrees. In looser usage, the term can describe anything arranged with twelvefold symmetry, such as a dodecagonal tower or table. Because it is precise and unambiguous, 'dodecagonal' is preferred over the plainer phrase 'twelve-sided' in scholarly and descriptive contexts, though it remains a relatively uncommon word outside specialist fields.
adjectiveHaving twelve sides and twelve angles; shaped like or relating to a dodecagon.
- Having twelve straight sides and twelve angles (of a plane figure).
- Shaped roughly like a dodecagon; arranged in twelve parts around a centre.
"The courtyard featured a striking dodecagonal fountain at its centre."
"The coin's unusual dodecagonal outline made it easy to identify by touch alone."
"Architects chose a dodecagonal plan for the pavilion to maximise the number of entrances."
The dodecagonal design of the Tower of the Winds in Athens has kept perfect time for over two thousand years.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of dodecagonal
Dodecagonal derives from Greek 'dōdeka' (twelve) combined with 'gōnia' (angle), via the Latinised form 'dodecagonus'. It was formed in English as the adjectival counterpart of the noun 'dodecagon', which entered the language during the Renaissance period when Greek mathematical vocabulary was widely adopted. Cognate terms from the same root include 'dodecahedron', denoting a twelve-faced solid, reflecting the same Greek numeral element.
Related word forms
How dodecagonal is actually used
A technical term used chiefly in geometry, mathematics, architecture, design, and numismatics. It is formal in register and rare in everyday conversation, where speakers would more likely say 'twelve-sided'.
Easily confused with dodecagonal
Dodecahedral describes a three-dimensional solid with twelve faces, whereas dodecagonal describes a flat shape with twelve sides.