More specifically, I guess I have a programming question. It seems like the examples in the library are only suited for one anchor and one tag. I would like to have 3 anchors transmitting a radius from the tag.

So, if you know where the anchors are (the centers of the circles) and three distances (the radii of the circles), you can draw a picture, right? Two circles intersect at 0 points, 1 point, or two points. If they don't intersect at all, you are out of range. If they intersect at one point, well, that's where you are. If they intersect at two points, you are at one of them. Which one is defined by the third circle.

Once you can see that visually, programming a solution is not too difficult.