Dreieck!

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Dreieck :]</title>

<style type="text/css">
    #triangle
    {
        border-color: white white red white;
        border-style: solid;
        border-width: 20px;
        width:0;
        height:0;
    }
</style>
</head>
<body>
    <div id="triangle">

    </div>
</body>
</html>