MathDB
A'B' > diameter of incircle, <A'C'B'=90^o

Source: 2006 Oral Moscow Geometry Olympiad grades 8-9 p3

October 17, 2020
geometrygeometric inequalityinradiusright angle

Problem Statement

On the sides AB,BCAB, BC and ACAC of the triangle ABCABC, points C,AC', A' and BB' are selected, respectively, so that the angle ACBA'C'B' is right. Prove that the segment ABA'B' is longer than the diameter of the inscribed circle of the triangle ABCABC.
(M. Volchkevich)