JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<div class="arrow-md arrow-down">
		<label for="usr">Name:</label>
  	<input type="text" class="form-control input-lg" id="usr">
</div>

CSS

.arrow-down {
	width: 0; 
	height: 0; 
	border-left: solid transparent;
	border-right: solid transparent;

	border-top: solid #f00;

	overflow: visible;
}

.arrow-md {
	border-width: 200px;
}

input {
	width: 200px;
	height: 75px;
}