Hello
Do you know where I can find the Option button/logo in Rhino educational version for Mac?
The term Options does not exist for Rhino/Mac. Try Rhino>Preferences instead… --Mitch
Hi Mitch
Thank you for your answer 
Do you also know, how to keep every new document i open in Millimeter? because everytime I open a new document it is always in Centimeters and I have to change it manually…
You can make all your customizations once (units, tolerance, line types, dimension styles, …) and save that file as a template (you can use the SaveAsTemplate command for this).
Then you can make Rhino use that file when it starts.
See “New” for more information.
Mac Rhino should have all the different templates installed same as Windows Rhino. From the splashscreen when you open a new document, you should see a templates section (going from memory here); choose the template Millimeters small or Millimeters large (should be both in there); and then somewhere there should be a check box that says “always use this template when Rhino starts”…
–Mitch
Thank you very much for your quick respons, I appreciate it very much 