peprendicular from I to AI,BI,CI lead to concurrent
Source: Sharygin Geometry Olympiad 2017 First Round P23 grades 10-11
July 23, 2018
geometryconcurrencyconcurrentperpendicular lines
Problem Statement
Let a line touch the incircle of triangle . The lines passing through the incenter and perpendicular to meet at points respectively. Prove that and concur.