CSS Traingle Comment Box

I am developing a comment box for our website and it seemed fun to us that it looks like a speech balloon.
I found this code online:

.arrow-up {
width: 0;
height: 0;
border-left: 6px solid transparent;
border-right: 6px solid transparent;
border-bottom: 9px solid #FFF;
margin-left: 27px;
margin-top: -9px;
}

Now we want to add a actual border to the triangle. ( 1px solid #000 )
Does anyone know how I can do this?

(bottom of triangle has no border needed)

Triangles in CSS are created using borders. You cannot add a border to a border so what your asking for cannot be done with CSS.

If you need that you will have to use a image instead.

Thanks! I've used a picture and no it works!