<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Hann</title>
<style>
.test{
width:0px;
height:0px;
border-left:50px transparent solid;
border-right:50px green solid;
border-top:50px transparent solid;
border-bottom:50px transparent solid;
}
</style>
</head>
<body>
<h2>純CSS繪製三角形</h2>
<div class="test"></div>
</body>
</html>
效果：
