</canvas>
<script type="text/javascript">
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "lightgray";
pincel.fillRect(0,0,600,400);
function dibujarCirculos(x,y,color,radio) {
pincel.fillStyle = color;
pincel.beginPath();
pincel.arc(x,y,radio,0,2*3*14);
pincel.fill();
}
dibujarCirculos(300,200,"red",10);
dibujarCirculos(300,180,"yellow",10);
dibujarCirculos(300,220,"blue",10);
dibujarCirculos(280,200,"orange",10);
dibujarCirculos(320,200,"black",10);
</script>
