<canvas width='600' height='400' ></canvas>
<script>
var tela= document.querySelector('canvas');// chama o canvas do html
var pincel= tela.getContext('2d');
pincel.fillStyle='black';
pincel.fillRect(0,0,600,400);
pincel.fillStyle='darkgreen'
pincel.fillRect(125,50,350,300);
pincel.fillStyle='black'//atributo
pincel.fillRect(180,100,90, 90);
pincel.fillStyle='black'//atributo
pincel.fillRect(340,100,90, 90);
pincel.fillStyle='black'//atributo
pincel.fillRect(270,190,70, 100);
pincel.fillStyle='black'//atributo
pincel.fillRect(230,240,40, 110);
pincel.fillStyle='black'//atributo
pincel.fillRect(340,240,40, 110);
</script> e