<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
.box {
border: 100px solid thistle;
width: 0px;
height: 0px;
border-top-color: transparent;
border-left-color: transparent;
border-right-color: transparent;
}
</style>
</head>
<body>
<div class="box"></div>
</body>
</html>
