MathDB
Easy Geometry

Source: Iran TST 2015, exam 1, day 1 problem 2

May 10, 2015
geometry

Problem Statement

IbI_b is the BB-excenter of the triangle ABCABC and ω\omega is the circumcircle of this triangle. MM is the middle of arc BCBC of ω\omega which doesn't contain AA. MIbMI_b meets ω\omega at TMT\not =M. Prove that TBTC=TIb2. TB\cdot TC=TI_b^2.