In a triangle
, let
,
,
be the midpoints of the sides
,
,
, respectively, and
,
,
be the midpoints of the arcs
,
,
of the circumcircle of
, not containing the vertices
,
,
, respectively. For
, let
be the circle with
as diameter. Let
be the common external common tangent to the circles
and
(for all
) such that
lies on the opposite side of
than
and
do.
Prove that the lines
,
,
form a triangle similar to
and find the ratio of similitude.
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In a triangle $ABC$, let $M_{a}$, $M_{b}$, $M_{c}$ be the midpoints of the sides $BC$, $CA$, $AB$, respectively, and $T_{a}$, $T_{b}$, $T_{c}$ be the midpoints of the arcs $BC$, $CA$, $AB$ of the circumcircle of $ABC$, not containing the vertices $A$, $B$, $C$, respectively. For $i \in \left\{a, b, c\right\}$, let $w_{i}$ be the circle with $M_{i}T_{i}$ as diameter. Let $p_{i}$ be the common external common tangent to the circles $w_{j}$ and $w_{k}$ (for all $\left\{i, j, k\right\}= \left\{a, b, c\right\}$) such that $w_{i}$ lies on the opposite side of $p_{i}$ than $w_{j}$ and $w_{k}$ do.
Prove that the lines $p_{a}$, $p_{b}$, $p_{c}$ form a triangle similar to $ABC$ and find the ratio of similitude.