If for instance, we set a -vendor-transform: rotate(40deg) css attribute on a rectangle
I found this... It's a working example plus info, demo and download link.
jquery-ui-rotation-using-css-transform -> live-demo
He use his own libraries, but if you are interest in the subject, you can read and learn how he get it.
cheers and good luck.
Gmo.-
Btw, the web is in Russian, but with google translate you can manage ;-)