MathDB

P9

Part of 2017 Sharygin Geometry Olympiad

Problems(1)

2 lines meet on the altitude

Source: Sharygin Geometry Olympiad Correspondence Round 2017 P-9 (Grade-8-9)

5/1/2017
Let C0C_0 be the midpoint of hypotenuse ABAB of triangle ABCABC; AA1,BB1AA_1, BB_1 the bisectors of this triangle; II its incenter. Prove that the lines C0IC_0I and A1B1A_1B_1 meet on the altitude from CC. Proposed by A.Zaslavsky
geometry