出典:Wiktionary
出典:『Wiktionary』 (2026/02/21 21:30 UTC 版)
polyiamond (plural polyiamonds)
Some authors also call the diamond (rhombus with a 60° angle) a calisson after the French sweet of similar shape.
出典:Wikipedia
出典:『Wikipedia』 (2010/11/06 07:10 UTC 版)
A polyiamond (also polyamond or simply iamond) is a polyform in which the base form is an equilateral triangle. The word polyiamond is a back-formation from diamond, because this word is often used to describe the shape of a pair of equilateral triangles placed base to base, and the initial "di-" looked like a Greek prefix meaning "two-".