Patent ID: 8011152

Claim:
A block suitable for use in an arrangement of blocks that are interlocked, said block comprising: a first side surface extending between a first edge and a second edge, said first side surface being irregular and having a first half and a second half that are congruent such that, when viewing the first side surface as a two-dimensional locus of points, the second half of the first side surface corresponds to a 180°-rotated version of the first half of the first side surface; a second side surface extending between said second edge and a third edge, said second side surface having a first half and a second half that are congruent such that, when viewing the second side surface as a two-dimensional locus of points, the second half of the second side surface corresponds to a 180°-rotated version of the first half of the second side surface; a third side surface extending between said first edge and a fourth edge, said third side surface being congruent with a first portion of said first side surface; a fourth side surface extending between said third edge and a fifth edge, said fourth side surface being congruent with a second portion of said first side surface such that said first portion and said second portion of said first side surface constitute said first side surface; and a fifth side surface extending between said fourth edge and said fifth edge, said fifth side surface having a first half and a second half that are congruent such that, when viewing the fifth side surface as a two-dimensional locus of points, the second half of the fifth side surface corresponds to a 180°-rotated version of the first half of the fifth side surface.