Iteration: GCSE(9-1) & A-Level
See the Pen Iteration for GCSE 9-1 and Pure Maths A-Level by VivaxSolutions (@VivaxSolutions) on CodePen.
You can practise iteration here by changing, x0 and the iterative formula in y.
Python Turtle - Polygons
This is the magic of Python Turtle. It can create amazing graphics with a few lines of code.