Y by Adventure10, Mango247
I will quote exactly at every letter.
Let
be a non-isosceles triangle with the incenter
. Let
, be the smaller circle through
tangent to both
and
(summation of indeces is done modulus 3). Let
, be the other intersection point of
and
. Prove that the circumcenters of the triangle
,
,
are collinear.
Let











