In geometry, a tetrahedron (plural: tetrahedra) is a polyhedron composed of four triangular faces, three of which meet at each vertex. A regular tetrahedron is one in which the four triangles are regular, or "equilateral", and is one of the Platonic solids. The tetrahedron is the only convex polyhedron that has four faces

The Tree of Life -- or Utterances of Sephirot -- is a mysterious Tetrahedron (a shape with four triangular surfaces) that can be traced back to Biblical times, and to this day it has great meaning to those who study Kabbalah. According to the story of Creation in the Book of Genesis, there were two divine trees in the Garden of Eden: the Tree of Life, and the Tree of Knowledge. Eventually, Adam and Eve "took a bite" at the Tree of Knowledge, but as a result lost direct access to the Tree of Life when they were subsequently expelled from the heavenly garden.