High school mathematics solid geometry is relatively simple. Because people who are afraid of mathematics can do it as long as they do more problems. You must learn painting from the teacher in class. Be sure to draw more. Don't be too ugly, the lines should be straight, and the picture must be large to be more intuitive. The geometric proof in the early stage must be easy to learn. Don't try to build a coordinate system. Geometric proof is a bit difficult and the system is simple. As long as you can build and calculate, you can do it. Hope to adopt