<!DOCTYPE html>
<html>
<head>
<style type="text/css">
body { margin: 0px; }
div {
box-sizing: border-box;
border: 1px solid black;
}
#left {
float:left;
width: 90px;
height: 190px;
}
#right {
float:right;
width: 90px;
height: 190px;
}
</style>
</head>
<body>
<div id=left></div>
<div id=right></div>
</body>
</html>