Sia

To use a class in HTML, you can add the "class" attribute to an HTML element. Here is an example:

If you want to apply a class named "example" to a paragraph element, you can do it like this:

$$\text{<p class="example">This is a paragraph with the class "example"</p>}$$

This way, you can style elements using CSS based on the class you have assigned to them. Let me know if you need more help with HTML!