There are two kinds of problems in high school:

It is the requirement of compulsory stage, that is, spatial imagination, that is, proving geometric conclusions through reasoning and deduction, which is rooted in the proof of traditional Euclidean geometry. Compared with finding a few squares, it only proves the distance and angle of a straight line, a straight line and a plane in computing space. The essence is to decompose a three-dimensional problem into a plane geometry problem (in a broad sense, it includes not only the concept of finding a few squares involved in junior high school, but also solving triangles and other problems) to find the answer.

It is the requirement of elective course 2- 1, which is to solve solid geometry with vector method. This essence is the idea of the combination of numbers and shapes and mutual transformation, and almost all problems have become vector calculation of fixed models.