Creating Triangles With Pure CSS

Several months ago, a post at WRD (CSS Tooltips Pointers With No Images) was sharing a technique which e as

As elements in HTML are square/rectangle shaped, creating a triangle using pure HTML/CSS may not seem to be possible.

However, as browsers draw borders at angles, it is possible to create an illusion which Jon Rohan is sharing in detail.

The technique simply uses a colored border with large pixels for one side of an element with leaving other sides transparent.

As expected, IE6 doesn't support this trick by default but Jon Rohan shows how to "hack" this with few CSS rules.

P.S. You may also want to check CSS Tooltips Pointers With No Images post at WRD which uses a similar technique.