MathDB
concurrency wanted , starting with AB + AC = 3 BC

Source: Czech-Polish-Slovak Junior Match 2017, individual p2 CPSJ

February 20, 2020
geometryconcurrencyconcurrent

Problem Statement

Given is the triangle ABCABC, with AB+AC=3BC| AB | + | AC | = 3 \cdot | BC | . Let's denote D,ED, E also points that BCDABCDA and CBEACBEA are parallelograms. On the sides ACAC and ABAB sides, FF and GG are selected respectively so that AF=AG=BC| AF | = | AG | = | BC |. Prove that the lines DFDF and EGEG intersect at the line segment BCBC