A construction done using only a Straightedge. The Poncelet-Steiner Theorem proves that all constructions possible using a Compass and Straightedge are possible using a Straightedge alone, as long as a fixed Circle and its center, two intersecting Circles without their centers, or three nonintersecting Circles are drawn beforehand.

**References**

Dörrie, H. ``Steiner's Straight-Edge Problem.'' §34 in *100 Great Problems of Elementary Mathematics: Their
History and Solutions.* New York: Dover, pp. 165-170, 1965.

Steiner, J. *Geometric Constructions with a Ruler, Given a Fixed Circle with Its Center.*
Translated from the first German ed. (1833). New York: Scripta Mathematica, 1950.

© 1996-9

1999-05-26