Thank you Garry & NotMyFault! Background of my question is that I am constructing Mobiles. The elements for the Mobiles I cut out with a lasercutter. When using shapes like "plates" – see picture – or any other flat objects I have to find out the center of gravity. I am aware that I have the option to SEE the center of rotation (supposing that this is the same like the center of gravity), but I also want to MARK it. I can mark the center with the pencil, but then I have to enlarge a lot and the result is still not very precise.
@NotMyFault: I came across the NASA explanation. Thanks for that. But having a CAD app, a lasercutter and being not very good in math, I hope for a simpler solutiion...
