1. 画一组同切圆

   >>> import turtle

   >>> turtle.circle(20)
   >>> turtle.circle(80)

2. 画一组同心圆

   >>> import turtle

   >>> turtle.circle(100)
   >>> turtle.up()
   >>> turtle.goto(0,50)
   >>> turtle.down()
   >>> turtle.circle(50)

3. 画一个五角星

   >>> turtle.reset()

   >>> import turtle
   >>> turtle.forward(100)
   >>> turtle.left(144)
   >>> turtle.forward(100)
   >>> turtle.left(144)
   >>> turtle.forward(100)
   >>> turtle.left(144)
   >>> turtle.forward(100)
   >>> turtle.left(144)
   >>> turtle.forward(100)

4. 画一个黄色实心五角星

   >>> turtle.fillcolor("yellow")

   >>> turtle.forward(100)
   >>> turtle.left(144)
   >>> turtle.forward(100)
   >>> turtle.reset()
   >>> turtle.color('yellow')
   >>> turtle.fillcolor("yellow")
   >>> turtle.begin_fill()
   >>> for i in range(5):
   turtle.forward(100)
   turtle.left(144)
   >>> turtle.end_fill()