MathDB
Paralell lines and tangent to (ABC)

Source: Turkey JBMO TST 2023 Day 2 P3

April 30, 2023
geometrytangent

Problem Statement

Let ABCABC is triangle and DABD \in AB,EACE \in AC such that DE//BCDE//BC. Let (ABC)(ABC) meets with (BDE)(BDE) and (CDE)(CDE) at the second time K,LK,L respectively. BKBK and CLCL intersect at TT. Prove that TATA is tangent to the (ABC)(ABC)