<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>正方形</title>
<style>
.chen{
width: 0;
height: 0;
background-color: aqua;
border-top: 250px solid #588cc7; /*如果想实现三角形，把其中三个背景色改为transparent即可实现 */
border-left: 250px solid #a4d7e1;
border-bottom: 250px solid rgb(124, 189, 214);
border-right: 250px solid cornflowerblue;
margin: 40px auto;
}
</style>
</head>
<body>
<div class="chen"></div>
</body>
</html>
