In the view:
<span ng-click="onItemClicked(currentItem)">click me</span>
<span ng-show="currentItem.isVisible">I'll be shown</span>
And in the controller:
$scope.onItemClicked = function (item) {
item.isVisible = true;
};
Read the documentation about ngShow.
Working demo: http://plnkr.co/edit/FEZ5JDfVfeWKSGOHjBSy?p=preview