How To Make A Triangle In CSS?

Hi guys,

I'm John (aka @codingdudecom http://www.coding-dude.com/). I'm a programmer
and graphic designer.

I've been working on an article about how many ways there are to create a
triangle in CSS. Here's the result of my work:
http://www.coding-dude.com/wp/css/create-a-triangle/

Would you please give me some feedback on these methods and please let me
know if you know alternative methods to achieve the same results
(preferably using only CSS, so no JS)

thanks,
John