Lycée Arago (Perpignan)
A convex N-gone is divided into triangles by its diagonals (assuming that 3 diagonals never intersect in the same point). The triangles are colored in red and in blue so that two triangles with a common side always have different colors. Find, in terms of N, the greatest possible value of the difference between the amount of red triangles and the amount of blue ones.
Type de présentation au congrès