how to get the rotation angle of a column

[alemanda]

Hi to all.
I have a problem.
I made a label for columns for structural representation purpose.
My question is the following: How can I get the rotation angle in plan (along its axis) of a column? I need this datum in order to write automatically parallel to the sides of the column the dimensions of it ...
Can anyone help me, please? Any suggestion?

[alemanda]

Sorry for the delay. That day i couldn't write anymore ...
Ok. I got it.
Thank you very much.
In this way my only limit is that I can manage rotation from 0 to 180 degrees (180 excluded) ... this is due to the values of label_position[3][1] and [3][2] ... is it?
Any way is great for me.
Thanks