<canvas width="350" height="300"></canvas>
<script>
var tela = document.querySelector("canvas");
var pincel = tela.getContext("2d");
pincel.fillStyle = "darkgreen";
pincel.fillRect(0,0, 600, 400);
pincel.fillStyle = "black";
pincel.fillRect(50, 50, 90, 90);
pincel.fillRect(200, 50, 90, 90);
pincel.fillRect(140, 140, 60, 100);
pincel.fillRect(100, 190, 40, 110);
pincel.fillRect(200, 190, 40, 110);
</script>
