O MEU MODELO

Meu modelo ficou assim:

<meta charset="UTF-8">

<canvas width="1000" height="800"></canvas>
<script>

    var pantalla = document.querySelector("canvas");
    var pincel = pantalla.getContext('2d');
    pincel.fillStyle = "white";
    pincel.fillRect(0, 0, 600, 400);

    pincel.fillStyle = "darkgreen";
    pincel.fillRect(0, 50,  350, 300);

    pincel.fillStyle = "darkblue";
    pincel.fillRect(50, 100, 90, 90);

    pincel.fillStyle = "darkblue";
    pincel.fillRect(210, 100, 90, 90);

   pincel.fillStyle = "darkblue";
    pincel.fillRect(140, 190, 70, 100);

    pincel.fillStyle = "darkblue";
    pincel.fillRect(105, 240, 40, 110);

    pincel.fillStyle = "darkblue";
    pincel.fillRect(210, 240, 40, 110);

</script>