Multiplication Using Lever of Similar Triangle

① This GeoGebra example demonstrates how to multiply two numbers using the geometric principle of a lever based on similar triangles, turning an arithmetic product into a visual ratio relationship. ② The core mathematical concept is the proportionality of corresponding sides in similar triangles, applied to construct a geometric multiplication model where segment lengths represent numbers. ③ Construction details: The example uses Point commands to create key points (N, n, M, m, etc.) and Segment commands to draw the lever-like triangle structure. Objects such as h, g, f, and nm help define the proportional relationships, while a text object (text1) displays the computed product. By dragging points, users can change the input numbers and observe the product update dynamically. ④ This is suitable for middle school and above students to explore the connection between geometry and arithmetic, and can serve as a hands-on activity for understanding similarity and proportional reasoning.