MathDB
Geometry

Source: Turkey Tst 2017 p3

March 30, 2017
circlesincentergeometry

Problem Statement

At the ABCABC triangle the midpoints of BC,AC,ABBC, AC, AB are respectively D,E,FD, E, F and the triangle tangent to the incircle at GG, HH and II in the same order.The midpoint of ADAD is JJ. BJBJ and AGAG intersect at point KK. The Cāˆ’C-centered circle passing through AA cuts the [CB[CB ray at point XX. The line passing through KK and parallel to the BCBC and AXAX meet at UU. IUIU and BCBC intersect at the PP point. There is YY point chosen at incircle. PYPY is tangent to incircle at point YY. Prove that D,E,F,YD, E, F, Y are cyclic.