<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
div{
width: 0px;
height: 0px;
border: 100px solid black;
border-right-color: transparent;
border-left-color: transparent;
border-top-color: transparent;
border-bottom-color: red;
}
</style>
</head>
<body>
<div></div>
</body>
</html>
