MathDB
2016 JBMO TST- Macedonia, problem 2

Source: 2016 JBMO TST- Macedonia

May 27, 2019
2016JMMOMacedoniaJuniorgeometryparallelogram

Problem Statement

Let ABCDABCD be a parallelogram and let EE, FF, GG, and HH be the midpoints of sides ABAB, BCBC, CDCD, and DADA, respectively. If BHAC=IBH \cap AC = I, BDEC=JBD \cap EC = J, ACDF=KAC \cap DF = K, and AGBD=LAG \cap BD = L, prove that the quadrilateral IJKLIJKL is a parallelogram.