```
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
body{
font: normal 14px "Microsoft YaHei",Tahoma,Helvetica,Arial,"\5b8b\4f53",sans-serif;
}
.content{
width: 100px;
height: 100px;
background-color: red;
border-radius: 5px;
clip-path: polygon(0% 0%,100% 0%,100% 75%,75% 75%,75% 100%,50% 75%,0% 75%);
/* clip-path: polygon(0% 0%, 100% 0%, 100% 75%, 75% 75%, 75% 100%, 50% 75%, 0% 75%); */
}
</style>
</head>
<body>
<div class="content">
<div class="banner">
</div>
</div>
</body>
</html>
```
