I want to create a link with read more text. if there are more than 3 lines in a paragraph this link should be visible and clicking on this it show display all the lines. >
For read more , you can use angular limitTo filter for limiting your paragraph to character's length instead of limiting paragraph to line numbers .
You can use something like this :
in html
{{myString | limitTo:numLimit}}
in controller
$scope.numLimit=200;
$scope.readMore=function(){
$scope.numLimit=10000;
};