Zaks

Zaks are a building toy originally produced by the company Ohio Art. They consist primarily of equilateral triangles and squares with toothed, hinged, and interlocking edges. The basic triangle and square shapes are further modified by having a number of different face styles, including holes or extended sockets that allow them to connect face-to-face. The toys can be attached to one another to build three-dimensional creations, with the edges either remaining rigid or being allowed to swivel. It is quite easy to create Platonic solids using Zaks, and the toys are useful to demonstrate how simple planes like triangles and squares can be used to create complex polyhedra. Since the pieces primarily connect with hinges, building a rigid structure takes some work, either by clever geometry or socketing together smaller polyhedra.

Zaks were manufactured through the late 1980s and early 1990s, production is now discontinued. They found some success, and can still be found for sale used.