If it is a parallelogram, the ordinate of point P is 3, and y=3 can be substituted into parabolic analytical formula. It is concluded that the X-axis of the intersection of the perpendicular line of AC connects the parabola and the P-point of the intersection of CE at point E, and the coordinates of the E-point can be obtained through similarity, and the coordinates of the P-point can solve the equations formed by the straight line CE and parabola.