Untitled

<html>
    <body>
        <div id="part1" style="border:1px solid black;width:100%;height:15%;"></div>
        <div id="part2" style="border:1px solid black;width:20%;height:80%;float:left;">
            <div id="part2-1" style="border:1px solid black;width:100%;height:60%;"></div>
            <div id="part2-2" style="border:1px solid black;width:100%;height:40%;"></div>
        </div>
        <div id="part3" style="border:1px solid black;width:80%;height:80%;float:right;"></div>
    </body>
</html>