You can use the sequence of Fibonacci to draw a spiral.[br][list][*]on two adjacent squares with side consecutive numbers in the sequence of Fibonacci you can draw a new square with side the next number in the sequence.[/*][*]In every quarter you can draw a circular so that the connected arcs form a spiral.[/*][/list]Strictly the figure isn't a real spiral since in a spiral there's a distance to a fixed point that constantly increases whereas in the Fibonacci circular arcs with different centers are drawn and the radius increases just every 90°.