6

from turtle import *

def moveto(x,y):
penup()
goto(x,y)
pendown()
def main():
setup(800, 600)
speed(0)

for radius in range(20, 200, 20):
   moveto(0, -radius)
   circle(radius)
   hideturtle()
   done()
if __name__ == '__main__':
 main()

from turtle import *

def moveto(x,y):
penup()
goto(x,y)
pendown()
def main():
setup(800, 600)
speed(0)

for radius in range(180, 0, -20):
moveto(0, -radius)
circle(radius)
hideturtle()
done()
if __name__ == '__main__':
    main()