Lester Circle Theorem, Triangle, Circumcenter, Nine-Point Center, First and Second Fermat Point, College, Mathematics Education. Distance learning.

Geometry Problem 905: Lester Circle Theorem, Triangle, Circumcenter, Nine-Point Center, First and Second Fermat Point. Levels: School, College, Mathematics Education

Lester Circle Theorem, Triangle, Circumcenter, Nine-Point Center, First and Second Fermat Point. Static Diagram

Given a triangle ABC (see figure above), the circumcenter O, Nine-point center N, First F₁ and Second F₂ Fermat points lie on a circle, called Lester circle.

This theorem was discovered by professor June A, Lester in 1996. Reference: June A. Lester, "Triangles III: Complex triangle functions", Aequationes Mathematicae, volume 53, pages 4–35, 1997.