**The Tetratans**

The three figures below were constructed from the 14 tetratans. The first three figures
were discovered by Henri Picciotto; the two hexagons (left) were first published (without
solutions) in December 1989. The upper right figure was first published in *SuperTangrams
for Beginners, Book 2* (Creative Publications, 1987, ISBN 0-88488-633-6; page 39;
solution page 42). These three figures have many solutions; the solutions below are
by Michael Keller. The fourth figure (below right) was discovered and solved by Ed Pegg. All four constructions show that
figures with bilateral (though not rotational) symmetry can be constructed with the full
set of tetratans, contrary to Martin Gardner's statement in chapter 11 (Polyhexes and
Polyaboloes, page 154) of *Mathematical Magic Show* (1978, Random House, ISBN
0-394-72623-5). The drawings were made with a commercial CAD program.

This article is copyright ©1999 by Michael Keller. All rights reserved.

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