Equilateral Triangle with a linear extruded frame

looking to make a wireframe structure with interchangeable text panels. proud of using trig and rounded corners (thx, Mathgrrl!)

.2 layer PLA. 10% infil (no supports)
LOTS of separation. (old? filament, supports, maybe?)
first step towards real designs.

Thanks to:
-OpenScadTutorial.org for all the preliminary instructions.
-Mathgrrl for the cointrap rounded corners solution.
http://makerhome.blogspot.com/2013_08_27_archive.html
-Wikipedia for helping me refresh trig memories with fundamental images.

http://en.wikipedia.org/wiki/List_of_trigonometric_identities#mediaviewer/File:Unit_circle_angles_color.svg
-My Wife and Son for putting up with me while I play and learn.