A nice study of the hands, but the protractor (or whatever it's called) is dominating the focus of the image. A different angle where the classic horseshoe shape is dominating the shot would have been more suitable to this particular challenge.
Showing a hobnailed horsefoot is a good idea, but the light from the flash is much too harsh and ruins the athmosphere. Also, a wider angle showing the man's head would have been good. 4.