通过这个程序可以画出这样的有意思的图形 补动图：
完整代码：
function tri
hold on,axis equal
axis([-1,41,-1,35])
set(gca,'xtick',[],'ytick',[],'xcolor','w','ycolor','w')
set(gca,'color','w')
times=20;
LW=1.2;
COLOR=[0 0 0];
k=1/8;
k2=0.8;
A=[0,0];
B=[40,0];
C=[20,20*sqrt(3)];
plot([A(1);B(1)],[A(2);B(2)],'color',COLOR,'Linewidth',LW)
plot([B(1);C(1)],[B(2);C(2)],'color',COLOR,'Linewidth',LW)
plot([C(1);A(1)],[C(2);A(2)],'color',COLOR,'Linewidth',LW)
for i=1:times
b=k*(C-B)+B;plot([A(1);b(1)],[A(2);b(2)],'color',COLOR,'Linewidth',LW);B=b;
pause(0.1)
c=k*(A-C)+C;plot([B(1);c(1)],[B(2);c(2)],'color',COLOR,'Linewidth',LW);C=c;
pause(0.1)
a=k*(B-A)+A;plot([C(1);a(1)],[C(2);a(2)],'color',COLOR,'Linewidth',LW);A=a;
pause(0.1)
LW=LW*k2;
end
end
