平面向量基本定理是平面向量内容中重要结论之一,相当多的学生对该定理的运用只限于平面几何中,甚至部分教师也这样认为.其实,只要在一个平面中,都可以运用这一定理,因此,这一定理又常称为共面向量定理.本文举例介绍运用共面向量定理解决立体几何中的线面平行问题,尤其是线面平行 The basic theorem of plane vector is one of the important conclusions in the content of plane vector, a considerable number of students use the theorem only in plane geometry, even some teachers think so .In fact, as long as in a plane, you can use this theorem , So this theorem is often called coplanar vector theorem.In this paper, we introduce the coplanar vector theorem to solve the problem of plane parallelism in solid geometry, especially the line parallelism