三角形中位线定理是平面几何的重要定理之一，它在几何证题中有着广泛的应用．关于这个定理的证明，除课本上的证法外，本文给出另一种证法，供同学们学习时参考．如图，在“ABC中，D、E分别是AB、AC的中点．求证：皿／BCH＿＿且＿＿DE一责BC．——－）—一我们知道，平行四边 The triangle median line theorem is one of the important theorems of plane geometry. It has a wide range of applications in geometrical proofs. As for the proof of this theorem, in addition to the proofs in the textbook, this paper gives another kind of proof for reference when the students learn. As shown in the figure, in "ABC, D and E are respectively the midpoints of AB and AC. Proof: //BCH__ and __DE is a BC.--) - we know that parallel sides