Now, since the points E and F are the circumcenters of triangles CIA and AIB, both of them lie on the perpendicular bisector of the segment AI. Hence, the line EF is the perpendicular bisector of the segment AI. Similarly, the lines FD and DE are the perpendicular bisectors of the segments BI and CI.
Katulad nito, E at F ay ang circumcenters ng triangles CIA at AIB. [Ito ay isang mahalagang katotohanan: na ang midpoint ng Arc BC sa circumcircle ng tatsulok ABC ay ang circumcenter ng tatsulok BIC.]