Y by
Let
be an acute triangle, let
be a median, and let
and
be the altitudes. Let
be the line perpendicular to
passing through
. Let
be the intersection point of
with
, and let
be the intersection point of
with
.
(a) Prove that
is the midpoint of
.
(b) Let
be the circumscribed circle of the triangle
, and let
and
be any two circles that have two points
and
in common, and are tangent to the segment
and the arc
of
not containing the point
. Prove that points
are collinear.













(a) Prove that


(b) Let











This post has been edited 2 times. Last edited by parmenides51, Dec 21, 2022, 9:57 PM