1<html xmlns="http://www.w3.org/1999/xhtml">
2<head>
3<style>
4.pad { padding: 100%; }
5</style>
6</head>
7
8<body>
9
10    <table>
11      <div class="pad">x</div>
12      <tr>
13        <td>a</td>
14        <td>b</td>
15        <div class="pad">c</div>
16      </tr>
17    </table>
18
19</body>
20
21</html>
22