画叠加的等边三角形

import turtle
turtle.screensize(800,800)
turtle.setup(800,500,100)
turtle.penup()
turtle.fd(-100)
turtle.pendown()
turtle.pensize(7)
turtle.pencolor("blue")
turtle.seth(-40)
turtle.fd(90)
turtle.right(60)
turtle.fd(90)
turtle.right(120)
turtle.fd(180)
turtle.right(120)
turtle.fd(180)
turtle.right(120)
turtle.fd(90)
turtle.right(60)
turtle.fd(90)
turtle.right(120)
turtle.fd(90)
turtle.done()