15th century contribution to the study of vaulted structure in Iran based on Ghiayth-al Din Kashani’s studies

Vaulted structure has been in use for nearly 4000 years and believed to have been studied by scientists and builders for nearly 2000 years. There are few publications about the geometry and constructional aspects of arches and vaults before Renaissance age. One of the most interesting works on this subject belongs to Jamshid Kashani known as a mathematician. Ghiayth Al-Din Kashani, has made some valuable contribution in the field of building construction in general and vaulted structures in particular. This paper aims to introduce and analyze a part of his work on building construction, that is on pointed arches. In this paper first we provide a short history of pointed arch. Then we will see a number of works from Roman period to Kashani age which had some contribution about arches. The third part of the paper deals with Kashaniʹs book Meftah Al-Hesab or the key of mathematics. The final section of the paper has devoted to Kasahniʹs contribution to pointed arches. And finally showing one of the calculation charts which could be used to find different parts of the arches can be the best case in the point.