MathDB

7

Part of 2005 JBMO Shortlist

Problems(1)

6 points in a parallelogram, two equal segments

Source: JBMO Shortlist 2005

10/13/2017
Let ABCDABCD be a parallelogram. P∈(CD),Q∈(AB)P \in (CD), Q \in (AB), M=AP∩DQM= AP \cap DQ, N=BP∩CQN=BP \cap CQ, K=MN∩AD K=MN \cap AD, L=MN∩BCL= MN \cap BC. Prove that BL=DKBL=DK.
geometryparallelogramJBMO