C1、C2、C的坐标 组合图形的形心算例 (2a1,y1),(2z2,y2),(za,y2) 已知b,c,t,求C的坐标 b A=bi b C+t C A,=(c-t) A=A1+A2=1(b+C-t) S=yA+vA 2 (b2+ct-t2) S,=4+=242=(b+c2-t)10 已知b, c, t ，求C的坐标 2 2 1 1 1 b y t A bt z = c = c = 2 2 ( ) 2 2 2 t y c t A c t t zc c = + = − = ( ) 1 2 A = A + A = t b+c −t ( ) 2 2 2 1 1 2 2 b ct t t Sz = yc A + yc A = + − ( ) 2 2 2 1 1 2 2 bt c t t Sy = zc A + zc A = + − c C z y C2 C1 b t t 0 C1、C2、C的坐标: ( , ), c1 c1 z y ( , ), c2 c2 z y ( , ) c c z y 组合图形的形心算例