MathDB
X56 Jumpscare

Source: USEMO 2024/3

October 26, 2024
geometryUSEMOUSEMO 2024

Problem Statement

Let ABCABC be a triangle with incenter II. Two distinct points PP and QQ are chosen on the circumcircle of ABCABC such that API=AQI=45. \angle API = \angle AQI = 45^\circ. Lines PQPQ and BCBC meet at SS. Let HH denote the foot of the altitude from AA to BCBC. Prove that AHI=ISH\angle AHI = \angle ISH.
Matsvei Zorka