I've never tired with IE7 but for IE8 I put the below html in. Which basically polyfills
HTML5 elements, CSS3 selectors and media queries. You might also want to look at es5 shims (https://github.com/es-shims/es5-shim). However, it you use all the native angular methods i.e. angular.forEach(...) you might be ok without this. As always you need to really test this in all browsers!!!!
<!DOCTYPE html>
<!--[if IEMobile 7 ]>
<html class="no-js iem7" xmlns:ng="http://angularjs.org" id="ng-app" ng-app="fsn"> <![endif]-->
<!--[if (gt IEMobile 7)|!(IEMobile)]><!-->
<html class="no-js" id="ng-app" ng-app="fsn">
<!--<![endif]-->
<head>
<!--[if lte IE 8]>
<script>
document.createElement('ng-include');
document.createElement('ng-switch');
document.createElement('ng-if');
document.createElement('ng-pluralize');
document.createElement('ng-view');
// needed to enable CSS reference
document.createElement('ng:view');
</script>
<![endif]-->
<!--[if lt IE 9]>
<script src="//cdnjs.cloudflare.com/ajax/libs/html5shiv/3.6.2/html5shiv.js"></script>
<script src="//s3.amazonaws.com/nwapi/nwmatcher/nwmatcher-1.2.5-min.js"></script>
<script src="//html5base.googlecode.com/svn-history/r38/trunk/js/selectivizr-1.0.3b.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/respond.js/1.1.0/respond.min.js"></script>
<![endif]-->
<meta charset="utf-8">
<script src="../vendor/modernizr/modernizr.js"></script>
</head>
It is also worth looking at the APIs that IE7 wouldn't support 'console' for example. The angular team say they only support down to IE8 with Angular <1.2.x so you might have to play about with it to get it to work smoothly.
I have IE8 working well but it does noticeably struggle with loading some larger pages as it is so slow.