Use the border-top-0 class in Bootstrap 4 to remove the top border.
Set the border-top-0 class:
<div class="mystyle border border-top-0"> Rectangle is missing the TOP border. </div>
Let us see an example to implement the border-top-0 class:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<style>
.mystyle {
width: 350px;
height: 170px;
margin: 10px;
}
</style>
</head>
<body>
<div class="container">
<h2>Heading Two</h2>
<div class="mystyle border border-top-0">
Rectangle is missing the TOP border.
</div>
</div>
</body>
</html>
