Excuse me, teacher, I have always used the method of building a department to do geometry, but how can I improve when I can't build a department and my three-dimensional thinking is not good?

You should also learn traditional solutions. Only by combining the two can we solve the problem better. Because the building method is not so easy to use at any time after all, provided that the graphics are relatively regular, this is its defect, which has to be compensated by traditional methods. In fact, traditional methods can't. The key is to skillfully use relevant theorems to determine the position relationship and find the angle. In particular, you can master the theorem of three perpendicular lines. Look for a few examples, ponder, should be very studious. Of course, this method is more of a spatial thinking. This can train your spatial thinking ability. Come on!