In a convex nonagon all the diagonals are drawn. These diagonals intersect each other at p points inside the nonagon, q points on the nonagon and r points outside the nonagon. Find the maximum possible value of p .
In a convex nonagon all the diagonals are drawn. These diagonals intersect each other at p points inside the nonagon, q points on the nonagon and r points outside the nonagon. Find the maximum possible value of p .