MathDB
2021 EGMO P4: Reflection of A over EF lies on BC

Source: EGMO 2021 P4

April 13, 2021
EGMO 2021geometryreflectionEGMOTriangle

Problem Statement

Let ABCABC be a triangle with incenter II and let DD be an arbitrary point on the side BCBC. Let the line through DD perpendicular to BIBI intersect CICI at EE. Let the line through DD perpendicular to CICI intersect BIBI at FF. Prove that the reflection of AA across the line EFEF lies on the line BCBC.
Back to ProblemsView on AoPS