Six-Point Circles from a Triangle

Abstract

In the Euclidean plane, let \( A \), \( B \), \( C \) be noncollinear points and \( T \) be the union of the lines \( AB \), \( BC \), \( CA \). It is shown that there is a point \( P \) such that if \( \tilde{T} \) is the image of \( T \) by any nonrotating uniform expansion about \( P \), then \( T \cap \tilde{T} \) is generally a six-point set that lies on a circle.