task3

from turtle import *
from random import random

def square(size=50, rgb='pink'):
    '''绘制正方形
    参数size指定边长
    参数rgb指定画笔颜色
    如果没有给参数，采用默认值
    '''
    pencolor(rgb)
    for i in range(4):
        fd(size)
        left(90)


def main():
    setup(800, 600)
    speed(0)

    n = 10
    for i in range(n):
        square(80,rgb = tuple( random() for i in range(3) ))
        left(360/n)

    hideturtle()
    done()


if __name__ == '__main__':
    main()

 task4

from turtle import *
import random
setup(800, 600)
pencolor((1,0,0.5))

n = 10
for i in range(n):
    # 绘制一片花瓣
    for j in range(2):
        speed(0)
        circle(80, 90)
        left(90)
    right(360/n)

hideturtle()
done()

 task5

from turtle import *

setup(800, 600)
bgcolor('black')
pencolor('white')
speed(0)

angle = 0
size = 2

n = 10
for i in range(n):
    for j in range(5):
        fd(size)
        angle += 72
        seth(angle)
        size += 5

hideturtle()
done()

 task6

from turtle import *
from random import random
def square(long=50,wide=25,rgb='black'):
    pencolor(rgb)
    for i in range(2):
        rgb = tuple(random() for i in range(3))  # 随机生成rgb颜色三元组 color(rgb)
        begin_fill()
        fillcolor(rgb)
        fd(wide)
        left(90)
        fd(long)
        left(90)
    fd(wide)
    end_fill()
def moveto(x,y):
    '''把画笔移至坐标(x,y)处'''
    penup()
    goto(x,y)
    pendown()
setup(800, 600)
bgcolor('white')
moveto(-300,0)
speed(0)
n=20
for i in range(n+1):
    square()

hideturtle()
done()