<!DOCTYPE HTML>
<html>
<head>
    <meta charset="utf-8">
    <title>42度空间-在css中绘制三角形-尖角向上的等边三角形演示</title>
    <style>
        .triangle-up {
            width: 0;
            height: 0;
            border-bottom: 100px solid red;
            border-left: 57.735px solid transparent;
            border-right: 57.735px solid transparent;
        }
    </style>
</head>
<body>
<div class="triangle-up"></div>
</body>
</html>