(1) Rotating drawings in dia, (2) virtual protractor for dia

[rhkramer gmail com]

I'm planning to make a new stand for my monitor (to get it as close to my desk 
as possible to relieve my neck ;-).  The existing stand leans forward by about 
1.5 degrees.  I need to cut an angle brace to support the upright with that 
1.5 degree forward lean.

To try to get the correct angles, I've drawn a diagram on dia, and I've 
measured the angles (close enough, I believe) by counting squares and using 
trigonometry.

But, it would have been slightly easier if either:

(1) I could rotate my drawing so the legs of the appropriate right triangle 
were parallel to the grid lines, 

Afaict, there is no way to rotate a drawing in dia (I couldn't find anything)


(2) I could find something that I might call a virtual protractor (I have 
protractors, somewhere, I just couldn't find any atm).  I googled for virtual 
protractors and they actually exist, but the one I found that looked most 
promising works only on chrome (apparently).

Does anybody (here) know of a virtual protractor that works on dia?

These are not desperate needs, because, as I mentioned, I think i've figured 
them close enough (as close as I can measure / cut them on my saw).

Thanks!