JSFiddle - React, Tailwind, and code Playground

HTML

<div class="content"></div>

CSS

.content {
	position: relative;
	width: 400px;
	height: 100px;
	background-color: pink;
}

.content::after {
	position: absolute;
	bottom: -100px;
	display: block;
	content: '';
	width: 0;
	height: 0;
	border-style: solid;
	border-width: 100px 200px 0 200px;
	border-color: #007bff transparent transparent transparent;
}