Problem 6.
Let
be an equilateral triangle. Let
be interior points of
such that
, , , and
Let
and
meet at
let
and
meet at
and let
and
meet at
Prove that if triangle
is scalene, then the three circumcircles of triangles
and
all pass through two common points.
(Note: a scalene triangle is one where no two sides have equal length.)
proposed by
Ankan Bhattacharya , USA