- Lester's theorem
In
Euclidean plane geometry , Lester's theorem, named afterJune Lester , states that in anyscalene triangle , the twoFermat point s, thenine-point center , and thecircumcenter areconcyclic .References
* Clark Kimberling, "Lester Circle", "Mathematics Teacher", volume 89, number 26, 1996.
* June A. Lester, "Triangles III: Complex triangle functions", "Aequationes Mathematicae", volume 53, pages 4–35, 1997.
* Michael Trott, "Applying GroebnerBasis to Three Problems in Geometry", "Mathematica in Education and Research", volume 6, pages 15–28, 1997.
* Ron Shail, "A proof of Lester's Theorem", "Mathematical Gazette", volume 85, pages 225–232, 2001.
* John Rigby, "A simple proof of Lester's theorem", "Mathematical Gazette", volume 87, pages 444–452, 2003.
* J.A. Scott, "On the Lester circle and the Archimedean triangle", "Mathematical Gazette", volume 89, pages 498–500, 2005.
* Michael Duff, "A short projective proof of Lester's theorem", "Mathematical Gazette", volume 89, pages 505–506, 2005.
* Stan Dolan, "Man versus Computer", "Mathematical Gazette", volume 91, pages 469–480, 2007.External links
* [http://thejuniverse.org/PUBLIC/LesterCircle/index.html The Lester Circle] Details of its discovery.
* [http://mathworld.wolfram.com/LesterCircle.html Lester Circle] atMathWorld
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