<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>使用border制作倒三角</title>
</head>
<body>
<style>
.arrow_01 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: blue transparent transparent transparent;
}
.arrow_02 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: transparent blue transparent transparent;
}
.arrow_03 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: transparent transparent blue transparent;
}
.arrow_04 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: transparent transparent transparent blue;
}
.arrow_05 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: blue blue transparent transparent;
}
.arrow_06 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: transparent transparent blue blue;
}
.arrow_07 {
width: 0;
height: 0;
border: 60px solid #000;
border-color: transparent blue blue transparent;
}
</style>
<div class="arrow_01"></div>
<div class="arrow_02"></div>
<div class="arrow_03"></div>
<div class="arrow_04"></div>
<div class="arrow_05"></div>
<div class="arrow_06"></div>
<div class="arrow_07"></div>
</body>
</html>
原文：http://www.cnblogs.com/wulianghai/p/4413776.html