Download AngularJS library from its Official Website. Then include the file within your page same as we include a jQuery library or any other JavaScript file.
<script type="text/javascript" src="angular.min.js"></script>
Or you can directly include from CDN
Now create a new HTML file index.html and include AngularJS script on it.
<!DOCTYPE html>
<html lang="en" ng-app="">
<head >
<meta charset="UTF-8">
<title>First AngularJS program</title>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.5/angular.min.js"></script>
</head>
<body >
<div >
40 + 50 = {{ 40+50 }}
</div>
</body>
</html>
it will produce the following output –
40 + 50 = 90