This is an Roman Arch. This contains 8 same and 1 key stone.The idea of making a Roman arch comes to my mind when I was searching a carpenter to build these blocks from wood/ply but was not able to get it done in proper dimensions and I wish, I could get this 3D printed.

This can be used to study basic physics concept of weight distribution and this will also help engineering and architecture students understand the making and working of "the structure of a Roman Arch".To extend, if one wants to understand basic roman arch, he has to print 9 stones of same shape and size(any stone or key stone) and to understand advance Roman arch i.e. with key stone, print them as they are.