17 is a Fermat Prime which means that the 17-sided Regular Polygon (the Heptadecagon) is Constructible using Compass and Straightedge (as proved by Gauß ).

**References**

Lefevre, V. ``Properties of 17.'' http://www.ens-lyon.fr/~vlefevre/d17_eng.html.

Shell Centre for Mathematical Education. ``Number 17.'' http://acorn.educ.nottingham.ac.uk/ShellCent/Number/Num17.html.

© 1996-9

1999-05-25