<!DOCTYPE html>
<html lang="en">
<head>
 <style>
 .parent {
 	width: 200px;
 	height: 200px;
 	overflow: hidden;
 	-webkit-clip-path: circle(100px, 100px, 100px);
 }
 .child {
 	height: 400px;
 	width: 200px;
 	margin:0;
 	padding:0;
 	background-color: green;
 }
</style>
</head>
<body>
<div class="parent">
<div class="child"></div>
</div>
</body>
</html>