<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 100px;
            margin: 100px auto;
            background-color: pink;
            position: relative
        }
        
        div p {
            position: absolute;
            top: -35px;
            left: 100px;
            transform: translateX(-50%);
            border-top: 10px solid transparent;
            border-right: 10px solid transparent;
            border-bottom: 10px solid green;
            border-left: 10px solid transparent;
        }
    </style>
</head>

<body>
    <div>
        <p></p>
    </div>

</body>

</html>