Our teacher specially said this question before the college entrance examination, that is, the question of space geometry. The math exam can be done with space vectors, but it must be guaranteed that no mistakes can be made. Because the teacher will have a grading standard when marking papers, and the solution of space vector does not appear in the answer as a formal solution. Once students use it when answering questions, they will be given full marks if they do it right, and will not be graded if they do it wrong, that is to say, they will be deducted completely.

So give a suggestion, if possible, try not to use space vector. If you are wrong, a big problem will be lost. If you can use the theorem knowledge of solid geometry, try to use this. After all, it is safer. If you are wrong in the middle, you will still get points in the front.