<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div style="width: 20%;background-color:red;float: left">1</div>
<div style="width: 80%;background-color:black;float: right">2</div>
<div></div>
</body>
</html>