<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
.duihua span.tp{
border-width: 30px;
border-style: solid;
border-color:transparent transparent red transparent;
left:40px;
top: -60px;
}
.duihua span.bo{
border-width: 30px;
border-style: solid;
border-color:transparent transparent #fff transparent;
left:40px;
top: -59px;
}
.duihua{
width: 300px;height:30px;border:1px solid red;
position: relative;left:100px;top:200px;background: yellow
}
.duihua i{position: absolute;width: 0;height: 0;font-size: 0;}
.duihua i.jiao{
border-width: 16px 16px 16px 8px;
border-style: solid;
border-color: transparent transparent transparent red;
left:300px;
top: -1px;
}
.duihua i.jiaob{
border-width: 16px 16px 16px 8px;
border-style: solid;
border-color: transparent transparent transparent yellow;
left:299px;
top: -1px;
}
</style>
</head>
<body>
<div class="duihua">
<span class="tp"></span>
<span class="bo"></span>
<i class="jiao"></i>
<i class="jiaob"></i>
</div>
</body>
</html>