<script>
window.onload = function() {
var canvas = document.getElementById("myCanvas");
var context = canvas.getContext("2d");

	for (var i=0; i<100; i++) {
	
				var x = i;
				var y = i;
				var w = 50+i*10;
				var h = 50+i*10;
				var a = Math.PI*2*i/100;
				
				square(x,y,w,h,a);
	
	}

///////////////////////// FUNCTION 

	function square(x,y,w,h,a) {
	
				context.save();
				context.translate(x,y);
				context.translate(w/2, h/2);
				context.rotate(a);
				context.rect(-w/2,-w/2,w,h);
				context.stroke();
				context.restore();
	
	}

};

</script>