N1,N2,N3 = The NPC centers of IBC, ICA, IAB, resp.
N11, N22, N33 = The NPC centers of N1BC, N2CA, N3AB, resp.
1. The lines N1N11, N2N22, N3N33 are parallel to Euler Line of ABC.
2. The Circumcenter of N1N2N3 is N, the NPC center of ABC.
Antreas P. Hatzipolakis, 13 April 2013