已知两不共线向量→AB和→AC,由平面向量基本定理知道:平面ABC内任一向量α都可由→AB、→AC唯一线性表示,即存在唯一一对实数x、y,使得α=→x AB+y→AC.基于此,本文将给出三角形的中线、角平分线、高线的向量表示及推广,并举例说明其应用.1.三角形中线的向量表示如图1,△ABC中,AM是BC边上的中线,则 Knowing that both non-collinear vectors  → AB and  → AC, we know from the basic theorem of plane vectors that any vector α in plane ABC can be uniquely represented by  → AB,  → AC, that is, there exists a unique pair of real numbers x , Y, such that α =  → x AB + y  → AC. Based on this, this paper will give a triangle of the median line, angle bisector, the line vector representation and promotion, and an example of its application. Vector representation shown in Figure 1, △ ABC, AM is BC on the edge of the line, then