Hey all,
I'm working through a geometry book and am currently stuck on a proof that asks me to show that, for a convex quadrilateral the line joining the midpoints of the diagonals and the lines joining the midpoints of the opposite sides pass through the same point. I'm stuck trying to figure out exactly what it means for three lines to pass through the same point in euclidean geometry. And then the rest of the proof of course. =0
Many thanks for your help,