This page lists all the references I know of (in any medium) about the Lester circle. If there are any missing, please and I'll add them here.
Note also that the Lester circle often occurs in the context of other geometrical constructs and explorations; search the Hyacinthos newsgroup for examples.
The original three papers:
| J. A. Lester, Triangles I: Shape. Equations Math. 52 (1996), 30 - 54 |
| J. A. Lester, Triangles II: Complex Triangle Coordinates. Aequationes Math. 52 (1996), 215 - 245 |
| J. A. Lester, Triangles III: Complex Triangle Functions. Aequationes Math. 53 (1997), 4 - 35 |
The paper that spread the word:
| Clark Kimberling, Lester Circle. Math. Teacher 89 (1996), 26 |
The centre of the Lester circle is listed as Center X(1116) in Kimberling's Encyclopedia of Triangle Centers (with additional information and a Geometer's Sketchpad sketch).
Michael Duff, A short projective proof of Lester's theorem. The Mathematical Gazette 89 (November 2005), 505 - 510 |
A trio by J.A.Scott.
J. A. Scott, Two more proofs of Lester's theorem. The Mathematical Gazette 87 ( November 2003), 553 - 556 |
J. A. Scott, On the Lester circle and the Archimedean triangle. The Mathematical Gazette 89, (November 2005), 498 - 500 |
J. A. Scott, On the Lester circle, a companion and another special case. The Mathematical Gazette 90 (March 2006), 141 - 143 |
H. Martyn Cundy, A journey around the triangle: Lester's circle, Kiepert's hyperbola and a configuration from Morley. The Mathematical Gazette 87 (July 2003), 217 - 229 |
| Ron Shail, A proof of Lester's Theorem. The Mathematical Gazette 85 (July 2001), 226 - 232 |
| B. Truscott, A new geometry result: The Lester Circle. Pithagoras 43 (August 1997), 26-27 |
A page on Eric Weinstein's Mathworld:
| Lester Circle, with an accompanying Mathematica notebook |
A page on Dick Klingens' homepage (in Dutch):
| Lester Cirkel, with an accompanying Cabri applet |
A page on David Fowler's site.
These
applets suffer from the switching Fermat
points problem.
Another Mathematica notebook and a paper, both by M. Trott:
| A Proof of Lester's Circle Theorem. http://library.wolfram.com/demos/v3/GeometryProof.nb. |
| M. Trott, Applying GroebnerBasis to Three Problems in Geometry. Mathematica Educ. Res. 6 (1997) , 15-28 |
A page on Wilson Strothers' site:
Contains a proof by inversive geometry (also discovered by J. Conway)
A page in Catalan: