Demorei pra calcular as coordenadas exatas, mas depois disso foi fácil.
<canvas width="600" height="400"></canvas>
<script>
var tela = document.querySelector('canvas');
var pincel = tela.getContext('2d');
var rectCoords = [[175, 110], [335, 110], [265, 200], [225, 240], [335, 240]];
var rectSizes = [[90, 90], [90, 90], [70, 100], [40, 110], [40, 110]];
pincel.fillStyle = 'darkgreen';
pincel.fillRect(125, 50, 350, 300);
pincel.fillStyle = 'black';
for (var i = 0; i < 6; i++) {
pincel.fillRect(rectCoords[i][0], rectCoords[i][1], rectSizes[i][0], rectSizes[i][1]);
}
</script>
