They may be arranged to form a regular hexagon with an inscribed black equilateral triangle or a regular hexagon with an inscribed red equilateral triangle. This is Wheeler's model 3HA. A drawing ...

Geometric Model by A. Harry Wheeler, Hexagon Transformable into Hexagon, Plane Dissection National Museum of American History. Click to open image viewer. Hinged Plane Dissection, Appears to be four ...