1. After reading the topic, you can draw or imagine the positional relationship between various line segments and the plane, and build a clear schematic topic map, which can help you solve the problem.

2. If the topic is difficult or can't be drawn or imagined, it means that there must be something reminding you in the topic. Just use the formula directly

In either case, as long as the relationship between line and line, line and surface, surface and surface is clear, remember the formula.

The most stupid way is to establish a coordinate system, all of which are expressed in coordinates. If you want to prove that it is vertical, you can go in and calculate it. If you want to prove that it is parallel, you can also bring it in for calculation, so you can pull it.