Hosein Naseri - Master of Architecture, Department of Architecture Jundi-shapur University of Technology, Dezful, Iran
Zahra Amini Farsani - Assistant professor of statistics, Department of Statistics, School of Science, Lorestan University, Khorramabad, Iran
Koorosh Attarian - Assistant professor, Department of Architecture Jundi-shapur University of Technology, Dezful Iran
Sadegh Bakhteari - Master of Architecture, Department of Architecture Jundi-shapur University of Technology, Dezful, Iran

Architecture through the ages, has embraced a wide variety of arts and sciences. By using mathematics, Iranian architecture has achieved a high level of beauty and perfection. tower is defined as a tall and thin structure with several sides used mostly for lookout and defense. The term shares the same meaning in Arabic and Persian. In this paper, the geometry and proportions of two tomb tower of Iranian Islamic architecture has been discussed by using Analytical and Descriptive Method. required data has been collected through Library documents. For Radkan-west tomb-tower, according to the shorter height of it, the thickness of the walls was sufficient in order to maintain its stability. Therefore, buttress has not been built. But for Gunbad -e Qābus according to the long height of the building, ten triangle shape buttresses have been used. These buttresses are visible in building views. The effort to increase building stability has impacted the design process of the building and it resulted in complexity of the geometry of the building and improvement of aesthetics values of the building.

Geometry, Proportions, Iranian tomb, Gunbad-e Qābus, Radkan-west.