info343/lectures/s5/resources/dom.css

div#rectanglearea {
   width: 600px;
   height: 200px;
   border: 1px solid black;
   overflow: hidden;
   position: relative;
}

div.rect {
   width: 80px;
   height: 80px;
   border: 2px solid black;
   position: absolute;
}