Python.

Turtle 1.

import turtle

for i in range(4):

silly = turtle.Turtle()
silly.color("Blue")
silly.forward(50)
silly.right(90)

silly.forward(50)
silly.right(90)

silly.forward(50)
silly.right(90)

turtle.done()

 

Turtle 2.

import turtle
silly = turtle.Turtle()

for i in range(4):
silly.forward(50)
silly.right(90)

silly.forward(50)
silly.right(90)

silly.forward(50)
silly.right(90)

silly.forward(50)
silly.right(90)

turtle.done()

 

Turtle 3.

import turtle

smart =turtle.Turtle()

for x in range(60):
for i in range (4):
smart.forward (50)
smart.right(90)
smart.right(6)

turtle.done()

 

Teaching Ideas.
Agbonline Teaching Exercises.
Using python.com
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Python Exercises.
Introduction to Python
Python exercises