from turtle import *
import math

def draw_tile(size):
    "Draws one tile, which can be repeated to form a pattern."
    draw_tile_outline(size)
    draw_cross(size)
    draw_triangle(size)
    draw_circle(size)

def draw_tile_outline(size):
    pencolor("#dddddd")
    square(size)

def draw_cross(size):
    pencolor("blue")
    fly(size/2)
    left(90)
    fly(size/4)
    right(90)
    cross(size/4)
    right(90)
    fly(size/4)
    right(90)
    fly(size/2)
    right(180)

def draw_triangle(size):
    pencolor("red")
    fly(size/8)
    left(90)
    fly(size/8)
    right(90)
    triangle(size/4)
    right(90)
    fly(size/8)
    right(90)
    fly(size/8)
    right(180)

def draw_circle(size):
    pencolor("gold")
    fly(size/2.5)
    left(90)
    fly(size/1.5)
    right(90)
    circle(size/8)
    right(90)
    fly(size/1.5)
    right(90)
    fly(size/2.5)
    right(180)

def fly(distance):
    "Moves without drawing."
    penup()
    forward(distance)
    pendown()

def square(size):
    "Draws a square of side length `size`"
    for side in range(4):
        forward(size)
        left(90)

def triangle(size):
    "Draws a triangle with side length `size`"
    for side in range(3):
        forward(size)
        left(120)

def cross(size):
     "Draws a cross in invisible square with side length `size`"
     left(45)
     forward(size*math.sqrt(2))
     right(45)
     fly(-size)
     right(45)
     forward(size*math.sqrt(2))
     left(45)
     fly(-size)