Wikipedia:Reference desk/Archives/Mathematics/2018 February 11

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February 11[edit]

Geometric naming[edit]

A 19th century polygonal fort.

Does the specific shape of this fort have a name in geometry? It's a polygonal fort. Alansplodge (talk) 11:30, 11 February 2018 (UTC)[reply]

I don’t know of any name that specifically refers to this, but it is one example of a concave hexagon with exactly one line of reflection symmetry. Loraof (talk) 14:57, 11 February 2018 (UTC)[reply]
Many thanks, I found Irregular Concave Hexagon which seems to fit the bill. Alansplodge (talk) 17:58, 11 February 2018 (UTC)[reply]
Please note that "Irregular Concave Hexagon" is an extremely general name which could be applied to almost anything (any 6-sided shape which is not convex). It's not a name for this particular shape. -- Meni Rosenfeld (talk) 08:21, 12 February 2018 (UTC)[reply]
True, but add Loraf's requirement for a line of symmetry, and also that each half is a right-angled trapezoid (trapezium in British English), and you have narrowed the possibilities to this type of design. Dbfirs 10:10, 12 February 2018 (UTC)[reply]
Thanks all. "No" seems to be the answer.... Alansplodge (talk) 01:32, 17 February 2018 (UTC)[reply]