# Exercice 2

from turtle import *

for _ in range(4):
    forward(100)
    left(90)

done()

# Exercice 3

from turtle import *

for _ in range(4):
    for _ in range(4):
        forward(100)
        left(90)
    left(90)
done()

# Exercice 4

from turtle import *

left(45)
for _ in range(4):
    forward(100)
    left(90)

done()

# Exercice 5

from turtle import *

# carré
left(45)
for _ in range(4):
    forward(100)
    right(90)

# diagonales
right(45)
forward(100*1.41/2)
for _ in range(4):
    forward(100*1.41/2)
    backward(100*1.41/2)    
    right(90)

done()

# Exercice 6

from turtle import *

for i in range(8):
    if i%2 == 0 :    
        forward(150)
        backward(150)
    else:
        forward(75)
        backward(75)
    right(360/8)

done()

# Exercice 7

from turtle import *

for i in range(12):
    if i%3 == 0 :    
        forward(150)
        backward(150)
    else:
        forward(75)
        backward(75)
    right(360/12)

done()

# Exercice 8

from turtle import *

for _ in range(6):
    forward(100)
    right(360/6)

done()

# Exercice 9

from turtle import *

for _ in range(8):
    forward(100)
    right(360/8)

done()

# Exercice 10

from turtle import *

# Décagone
for _ in range(10):
    forward(20)
    right(360/10)

# Double-Décagone
for _ in range(20):
    forward(20)
    right(360/20)

done()

# Exercice 11

from turtle import *

# Avec circle
circle(50, 360)

# Ou avec 50 segments
for _ in range(50):
    forward(10)
    right(360/50)

done()