Tetrahedrons have been designed and a few proto-types have been made.A tetrahedron is a four sided pyramid like structure, each side having 3 60* angles and each corner piece holds three bars. Essentially, thestructure stays the same no matter which way it is set up.(see photos in the "Tetrahedron" folder) The tetrahedron represents the element of fire ("pyra" in latin). The Tetrahedron represents the concept of system. When four radiating points interact, they will form the Tetrahedron.It has four triangular faces, and is the structural basis for geodesic architecture. As the sphere represents the Absolute, the Tetrahedron; being the next platonic solid to be seen in nature, represents Truth.For more information... http://en.wikipedia.org/wiki/Tetrahedron http://mathworld.wolfram.com/Tetrahedron.html or about other geometric applications, check out the Buckminster Fuller institute... http://www.bfi.org/