Tesseract

The Tesseract is a four dimensional object created by extruding a cube within the mathematical 4th dimension. In a cube, every edge is shared by 2 squares. In a tesseract, 3 squares meet at every edge. Also the tesseract has 16 vertices, 32 edges, 24 squares, and 8 cubes.

A tesseract is defined by the set of points: {(x,y,z,h): 0 £x £ 1, 0 £ y £ 1, 0 £z £ 1, 0 £h £ 1}

See also [[1]] for an illustration.