@article {MATHEDUC.06282934,
author = {Oai, Dao Thanh},
title = {A simple proof af Gibert's generalization of the Lester circle theorem.},
year = {2014},
journal = {Forum Geometricorum},
volume = {14},
issn = {1534-1178},
pages = {123-125},
publisher = {Florida Atlantic University, Department of Mathematical Sciences, Boca Raton, FL},
abstract = {The Lester circle theorem states that in any triangle, both Fermat points, the nine point center and the circumcenter lie on a circle. This admits a generalization given by Gilbert: every circle whose diameter is a cord of the Kiepert hyperbola perpendicular to the Euler line passes through the Fermat points. This paper gives a simple proof of this last statement based only on simple properties of rectangular hyperbolas.},
reviewer = {Antonio M. Oller (Zaragoza)},
msc2010 = {G75xx},
identifier = {2014e.00580},
}