
The Archimedean spiral is a spiral named after the Greek mathematician Archimedes.



An Archimedean spiral can be described by the equation:






r
=
a
+
b
θ


{\displaystyle \,r=a+b\theta }


with real numbers a and b.



Task
Draw an Archimedean spiral.




  [ $ "turtleduck.qky" loadfile ] now!
  turtle
  0 n->v 
  900 times 
    [ 2dup walk
      1 20 v+
      1 36 turn ]
  2drop