a,b的重心为
d:[(x1+x2)/2,(y1+y2)/2]
则 c,d的重心为
o:[(x1+x2+2x3)/4,(y1+y2+2y3)/4]
同理:
o:[(x2+x3+2x1)/4,(y2+y3+2y1)/4]
o:[(x3+x1+2x2)/4,(y3+y1+2y2)/4]
三式相加
3o:=(x1+x2+x3,y1 + y2 + y3)
∴重心o为((x1 + x2 + x3)/3,(y1 + y2 + y3)/3)
a,b的重心为
d:[(x1+x2)/2,(y1+y2)/2]
则 c,d的重心为
o:[(x1+x2+2x3)/4,(y1+y2+2y3)/4]
同理:
o:[(x2+x3+2x1)/4,(y2+y3+2y1)/4]
o:[(x3+x1+2x2)/4,(y3+y1+2y2)/4]
三式相加
3o:=(x1+x2+x3,y1 + y2 + y3)
∴重心o为((x1 + x2 + x3)/3,(y1 + y2 + y3)/3)