It is given triangle ABC such that ∠ABC=3∠CAB. On side AC there are two points M and N in order A−N−M−C and ∠CBM=∠MBN=∠NBA. Let L be an arbitrary point on side BN and K point on BM such that LK∣∣AC. Prove that lines AL, NK and BC are concurrent geometryparallelconcurrent