# A Triangle Formed by the Centers of Three Nine-Point Circles

A Triangle Formed by the Centers of Three Nine-Point Circles

Let ABC be a triangle and let A', B', and C' be the midpoints of BC, AC, and AB, respectively. Let A'', B'', and C'' be the centers of the nine-point circles of the triangles AB'C', BC'A', and CA'B', respectively. Then A''B''C'' is homothetic with ABC in the ratio 1:2.

In the figure s(XY) is the slope of XY.