div {
	position: absolute;
	top: 200px;
	left: 200px;
	display: inline;
	background-color: green;
	padding: 20px;
	border-radius: 20px;
}
div:after {
	content: "";
	position: absolute;
	bottom: -15px;
	left: 25px;
	border-style: solid;
	border-width: 15px 15px 0;
	border-color: green transparent;
}