Turtle Geometry

Drawing shapes with loops

An interactive lesson with 8 steps, about 7 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• A turtle draws by repeating "forward, turn".
• A simple closed shape needs 360° of turning in total.
• Regular n-gon: turn 360°/n; stars turn several full circles.

Steps

1. A drawing turtle
2. A hexagon
3. Nine sides
4. The total turning theorem
5. Counting the turns
6. Inside an octagon
7. A five-pointed star
8. When does it close?