Y by
Let
be a triangle and
be the foot of the bisector of
. Let
and
be the circumcenters of
and
respectively and let
and
be the projections of
and
through the bisectors of the angles
and
respectively. The incircle of
touches
and
at points
and
respectively and the bisectors of angles
and
meet the perpendicular bisector of
at points
and
respectively. Prove that the five lines
and
are all concurrent.
























