All space geometry problems can be solved by establishing a system, which is no problem but not recommended. Similar knowledge in junior high school is a simplification of the system from a certain angle. You might as well use the construction system to understand similarity, and you will find that although the construction system is logical, similarity is very fragrant to use.

Sometimes the establishment of the system is really intuitive, but sometimes it is more troublesome to calculate. In the process of establishing the system, it is usually something that needs careful consideration, so the establishment of the system is the best policy. If you can use pure geometry, use pure geometry. After all, the establishment of the system requires high calculation.