Investigating and Analyzing the Geometric proportions of the Works of Qavam al-Din Shirazi: A Case Study of Goharshad Mosque in Mashhad and Goharshad Mosque in Herat

Qavam al-Din Shirazi was one of the prominent architects of the Timurid era who has left many works in memories such as the Goharshad Mosque in Mashhad and the Goharshad Mosque in Herat. What is considered as an architectural work in the study of a building is the material and physical aspects of the architectural space. Due to the destruction of Herat's Goharshad Mosque, one of the ways to understand the architecture of the mosque is to examine its geometric proportions with the Goharshad Mosque in Mashhad because the Goharshad Mosque in Mashhad was built before the Herat Goharshad Mosque, and it is possible that Qavam al-Din used common geometric proportions in the design of the mosques. Therefore, the present study aims to find a common geometric proportions system in two Qavam al-Din index buildings, namely Goharshad Mosques in Mashhad and Herat, to analyze and compare the geometric proportions of the ground floor plan of these mosques. The research method used in this research is historical-commentary. Data collection was done in two sections: library and document analysis and maps. As such, geometric proportions of Goharshad mosques in Mashhad and Herat were analyzed and compared using geometric proportions patterns. The research results show that Qavam al-Din used similar geometric proportions and ratios in these mosques. In other words, in both mosques, the dome, the length of the prayer hall, and the combination of the dome complex with the prayer hall have similar geometric proportions and there are differences in the Geometric proportions and ratios of the central courtyard and porches of the two mosques that may be related to the context (location of the building) and the type of use.