+ static void FindTangents(Object *, Point);
+ static void FindTangents(Object *, Object *);
+ static Point NearestTo(Point, Point, Point);
+ static Vector GetNormalOfPointAndLine(Point, Line *);
+ static Circle FindCircleForThreePoints(Point, Point, Point);
+ static double Determinant3x3(double, double, double, double, double, double, double, double, double);
+ static Arc Unpack(Point, Point, double);