Product Introduction This demonstrator consists of a demonstration board (round demonstrator and regular polygon demonstrator are equipped with colored rubber bands), plastic discs, magnetic seats, and magnetic plastic sheets that can be lapped to form different parallel lines and triangles, and a demonstrator for the position relationship between two circles. The supporting feet of the demonstration board can be erected on the desktop, the plastic discs can be adsorbed on the blackboard with a magnetic base, the overlapped plastic sheets can be combined into different geometric figures and angles with the connector pins, the sheets can be overlapped with each other, the quadrilateral subordination diagram, the right angle three-phase corresponding to the Pythagorean law diagram, etc.