And now ... the moment you've been waiting for!
The secret behind this wonderful picture.

Firstly, let's simplify it a bit: Exercise 14 Can you write down the first 9 steps? Check.

So we could start with:

to spiral :distance
  forward :distance right 92

and now for the tricky bit ... we want to do the same thing again but for a distance of 5 less ... here's how:

  spiral :distance - 5
end

Exercise 15 Try it. Check. Not quite what we wanted! We need a way to stop the turtle when :distance becomes small. Here's how:

if :distance < 2 [stop]

Exercise 16 See if you can finish the spiral. Check.