Take any line not parallel to any line through two points. Start with all points on one side. Rotate the line until it passes through a point. Each time the line passes a point, the count changes by 1.
Wait correct: For triangle ABC, transversal line through E (on AB), F (on AC), and D (on BC), Menelaus says: rmo 1993 solutions
Find all positive integers ( n ) such that ( n^2 + 1 ) divides ( n! ). Take any line not parallel to any line through two points