Introduction to Heptiamonds 
Heptiamonds (pronounced hepteyemonds) are a member of the Polyforms puzzle family, which comprises sets of puzzle pieces based on squares (Polyominoes), triangles (Polyiamonds) or hexagons (Polyhexes). The Heptiamonds are a set of twentyfour puzzle pieces (called animals among Polyform enthousiasts), each representing one of the twentyfour possible ways to combine seven equilateral triangles by laying them sidetoside on a plane (picture below). The term Polyiamonds was coined in 1961 by T.H. O'Beirne who suggested that if a diamond (rhombus) has two such triangles, a polyiamond can have any amount of them. Consequently, a heptiamond is an animal with seven triangles. A full set of Heptiamonds has 24 x 7 = 168 equilateral triangles, which I call Basic Triangles. A grid of equilateral triangles (known as an isometric grid) showing the twentyfour The aim of the game is to fit the pieces, without overlaps, into a configuration, which I call a Shape (cf. solved image in picture). The procedure is much like a classical jig saw puzzle but with these essential differences:
Each Shape contains 168 Basic Triangles, unless one chooses to solve modified puzzles with, for instance, OneSided Heptiamonds (described in some of the outside links). This site contains only solutions of the standard set of twentyfour.
