A heptiamond is a figure made of seven equilateral triangles joined
edge to edge.
A Galvagni figure is a figure that can be tiled by a polyform
in more than one way—a kind of self-compatibility figure.
A Reid figure is a Galvagni figure without holes.
All the heptiamond Galvagni figures
and most of the Reid figures
were found by
Dr. Michael Reid
of the University of Central Florida.
Galvagni Figures
2 Tiles
3 Tiles
4 Tiles
6 Tiles
Unsolved
Reid Figures
Hypersymmetric
Joint
Neither the M heptiamond nor the V heptiamond is known
to have a Reid Figure.
They can form a Reid Figure when used together: