Monopoly

Start at 12 degrees to the east of due north.

Travel ‘r’ meters to the centre.

Rotate 19 more degrees towards due east.

Travel ‘r’/2 meters away from the centre.

Now begin again without overlapping.

Start at due west.

Travel ‘r’ meters to the centre.

Rotate 127.5 degrees until you are 52.5 degrees south of due east.

Travel ‘r’/2 meters away from the centre.