It is very convenient to draw mathematical figures with geometric sketchpad. If you are a math teacher, it is good to learn to use the geometry sketchpad. Many math teachers are using the geometry sketchpad.

Plane geometric shadows can be made into any shape, whether it is a strip or a grid, but you have to learn how to use them first.

There is a beginner's video told by teacher Wang Xinchang on the Internet. Below is his website, and there is a geometric sketchpad video.

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