import turtle

bob = turtle.Turtle()

#畫四方形
def square(t,length):


    for i in range(4):
        t.lt(90)
        t.fd(length)

square(bob,200)

#畫多邊形
def polygon(t,length,n):


    for i in range(n):

        t.lt(360/n)
        t.fd(length)


polygon(bob,50,30)


#畫圓形
def circle(t,r):

    for i in range(1000):
        t.lt(360 / 1000)
        t.fd(3.14*2*r/1000)

circle(bob,100)

python 的turtle 簡易畫圖，第一次