定义多点坐标，给出折线，并计算起始点和重点距离

import turtle
import math

定义多个点的坐标

x1,y1=100,100
x2,y2=100,-100
x3,y3=-100,-100
x4,y4=-100,100

绘制折线

turtle.penup()
turtle.goto(x1,y1)
turtle.pendown()

turtle.goto(x2,y2)
turtle.goto(x3,y3)
turtle.goto(x4,y4)

计算起始点和终点的距离

distance=math.sqrt((x1-x4)2+(y1-y4)2)
turtle.write(distance)