2016 APMO Problems/Problem 3
Problem
Let and
be two distinct rays not lying on the same line, and let
be a circle with center
that is tangent to ray
at
and ray
at
. Let
be a point on segment
. The line through
parallel to
intersects line
at
. Let
be the intersection of lines
and
, and let
be the intersection of line
and the line through
parallel to
. Prove that line
is tangent to
.