A non-isosceles triangle
has sides
,
,
with the side
lying opposite to the vertex
. Let
be the midpoint of the side
, and let
be the point where the inscribed circle of triangle
touches the side
. Denote by
the reflection of the point
in the interior angle bisector of the angle
. Prove that the lines
,
and
are concurrent.
%V0
A non-isosceles triangle $A_{1}A_{2}A_{3}$ has sides $a_{1}$, $a_{2}$, $a_{3}$ with the side $a_{i}$ lying opposite to the vertex $A_{i}$. Let $M_{i}$ be the midpoint of the side $a_{i}$, and let $T_{i}$ be the point where the inscribed circle of triangle $A_{1}A_{2}A_{3}$ touches the side $a_{i}$. Denote by $S_{i}$ the reflection of the point $T_{i}$ in the interior angle bisector of the angle $A_{i}$. Prove that the lines $M_{1}S_{1}$, $M_{2}S_{2}$ and $M_{3}S_{3}$ are concurrent.