研磨自：[url=https://www.bilibili.com/video/BV1aB4y1x7NZ/?spm_id_from=333.788.recommend_more_video.3&vd_source=edcad05029f6d4b15eaba8a422397416]【GGB教学】（指令）折线图2-绘制三角形曲线_哔哩哔哩_bilibili[/url][br]

l1={A,B,C,A}[br]l2=x(l1)[br]l3=y(l1)[br]f(x)=折线图(0...3,l2)[br]g(x)=折线图(0...3,l2)[br][br]a=曲线=(f(t),g(t),t,0,3)[br][br][br]b=滑动条(0,3,0.01)[br]赋值(b,0)[br][br]eq1:x=b[br][br]D=交点(eq1,f)[br]#D=(b,f(b))[br][br]E=交点(eq1,g)[br]#E=(b,g(b))[br][br]F=a(b)[br]#F=(f(b),g(b))[br][br]#启动动画b,明显不匀速，线段长时快，线段短时慢，每段用时一样