This is the basis and problem of a plane vector, and the common solving methods are as follows:

① plane vector basic theorem method: this method needs vector transformation, and we can try this method in a complete closed graph;

② System-building method: This method is very quick and simple to deal with many vector problems, mainly because everything becomes orderly after the system is built, and the problems before the system are complicated and disorderly, so this kind of problems give people a stiff feeling;

③ Equal sum line method: This method also makes a length rule to make the problem orderly. When the angle is known or the length can be found, it will simplify the problem to deal with the substrate and the problem with equal sum lines.