[rod]

Great info johnny0... Led me to figuring this out:

set h to x of size of self
set w to y of size of self
set text of self to (h / 72) * (w / 72) as text

I don't know the significance of "72" here yet, but this appears to work for squares/rectangles. Of course this won't work for custom shapes. It would be cool to figure out how to subtract the custom shape from the bound rectangle and figure the area of that, but I am just getting started.. I think I will work on circle and triangles next.