Prof. Dr. Sead Rešić, Prof. Dr. Maid Omerović,
Anes Z. Hadžiomerović, Ahmed Palić
Bosnia and Herzegovina
Abstract. In this section we deal with an interesting fact which will imply ABCD some well known theorems. Namely we prove that in a convex quadrilateral whose diagonals meet at O, the midline of the triangle ∆BOC parallel to BC, the midline of the triangle ∆AOD parallel to AD, and the midline of the quadrilateral ABCD connecting the sides AB and CD meet at one point, or are parallel.
Keywords: Ceva; Menelaus; Stewartes; cevian; concurrency; collinearity; Fermat; Torricelli