<canvas width="600" height="400"></canvas>
<script>
var tela = document.querySelector('canvas');
var pincel = tela.getContext('2d');
pincel.fillStyle = 'lightgrey';
pincel.fillRect(0, 0, 600, 400);
pincel.fillStyle = 'darkgreen';
pincel.fillRect(125, 50, 350, 300);
pincel.fillStyle = 'black';
pincel.fillRect(175, 100, 90, 90);
pincel.fillRect(335, 100, 90, 90);
pincel.fillRect(265, 190, 70, 100);
pincel.fillRect(225, 240, 40, 110);
pincel.fillRect(335, 240, 40, 110);
</script>
