Turtle graphics with Python

Lesson overview

Topic

Turtle graphics

Level

GCSE

Learning objective

Use Turtle commands and loops to draw a repeated shape and explain how the turn angle affects the result.

1.Predict

Example code

import turtle

t = turtle.Turtle()
for _ in range(4):
    t.forward(100)
    t.left(90)

• What shape do you think the turtle will draw by the end of the loop?
• How many times will the turtle move forward before the program stops?

2.Run

Open the code in Paired, run it, and compare the drawing with your prediction.

3.Investigate

• The loop repeats the same two commands several times.
• Each forward command draws one side, and each left turn changes the direction for the next side.

• Why does left(90) help the turtle make a square?
• What role does range(4) play in the program?
• What shape would appear if the turn angle changed but the loop still ran 4 times?

4.Modify

• Change the distance so the square is larger or smaller.
• Change the angle and observe how the drawing changes.
• Add a colour or pensize command before the loop starts.

5.Make

Create your own Turtle program that draws a different repeated shape, such as a triangle, hexagon, or simple pattern.

Extension

Use another loop or a colour change to build a repeating pattern and explain how your angles control the final design.