Circular Patterns and Sea Shells

We already learned the SPIN command. The effect is to rotate and redraw a picture symmetrically around a fixed point (defined by the turtle).  The effect of the new command SPINR  is similar but the turtle keeps moving and not just turning.  For example, the command SPIN 4 [FD 50] make a plus sign while SPINR 4 [FD 50] will make a square to the right of the turtle.  similarly, SPINL 4 [FD 50] will make a square to the left of the turtle.

Here are some further example that illustrate the SPINR and SPINL commands:

SPINR 5 [FD 50]
SPINL 3 [FD 40]


SPINR 4 [CURVER 120 70]


SPINR 6 [CURVER 120 70 ]

Practice exercises

Additional exercises

Click to see the picture of the exercise

Paper Test: