设,三顶点A(x1,y1),B(x2,y2),C(x3,y3)则重心O[(x1+x2+x3)/3,(y1+y2+y3)/3]向量OA=[x1-(x1+x2+x3)/3,y1-(y1+y2+y3)/3]向量OB=[x2-(x1+x2+x3)/3,y2-(y1+y2+y3)/3]向量OC=[x3-(x1+x2+x3)/3,y3-(y1+y2+y3)/3]则,向量OA+...