验证力的平行四边形定则是高中物理中的一个传统学生分组实验。因实验所需器材常见、易购,多年来该实验一直未曾改进。我们在长期的实验教学中发现:用图钉将白纸固定在图板上做实验,图板上会留下很多针孔,时间一长,图板只好报废;再者每次用后均需用起子将图钉拔出以便下次再用, The verification parallelogram rule is a traditional student grouping experiment in high school physics. Due to the common and easy-to-order equipment required for the experiment, the experiment has not been improved over the years. In the long-term experimental teaching, we found that using a push pin to fix the white paper on the drawing board for experimentation, many pinholes are left on the drawing board. Over time, the drawing board has to be scrapped; after each use, it is needed. The screwdriver pulls out the thumbtack for the next time,