private static float Area(Pnt2d p, Pnt2d q, Pnt2d r) { return((q.Y - p.Y) * (r.X - q.X) - (q.X - p.X) * (r.Y - q.Y)); }
private static float CompareX(Pnt2d a, Pnt2d b) { return(a.X - b.X); }