Geometry Sketchpad is a good software for learning mathematics. It was invented by Americans, and/kloc-0 was introduced to China by the State Education Commission in 1996. Therefore, the application of graphic information technology in many textbooks is its work. Later, an American student's graduation thesis design is a software, which is also very popular in the world. It is GeoGebra, or GGB for short. Because there is no promotion by the State Education Commission, its popularity is not great, but it is also a good math learning software. There are some others. If you want to learn to use them, it is recommended to use the geometric sketchpad.