how to add horizontal line in html page code example

Example 1: html horizontal line style

<!-- HTML -->

<!-- You can change the style of the horizontal line like this: --> 

<hr style="width:50%", size="3", color=black>  


<!-- Or like this: -->

<hr style="height:2px; width:50%; border-width:0; color:red; background-color:red">

Example 2: which is right or in html

<hr> <!--   it represents a horizontal line break, in HTML4.0 we use <hr>, 
            in XHTML1.0 we use <hr/>,  in HTML5(which is the current version of 
            HTML) we can use both <hr> and <hr/>    
       -->