Turtle spiral

for (var i=0;i<100;i++){ t.forward(i*3); t.left(71); }

Source code

<jsxgraph width="600" height="600">
var brd = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-300, 300, 300, -300]});
var t = brd.create('turtle');

function run() {
  brd.suspendUpdate();
  var code = document.getElementById('inputtext').value;
  if (code=='') { return; }
  eval(code);
  brd.unsuspendUpdate();
}
function clearturtle() {
  t.cs();
}
run();
</jsxgraph>

• Hints how to "Slow the turtle down"

External links

• A similar construction with GeoGebra
• ZUM-Wiki's Turtle graphics page