A possible use of the Kha's protractor

I have recently proposed that an object, found in an Egyptian tomb and exposed at the Egyptian Museum of Torino, could be a protractor. The tomb was that of architect Kha, supervisor at Deir El-Medina during the 18th Dynasty, and his wife Merit. Considering then the object as a protractor, the architect could have used it to measure the angle of the inclined planes.