Abstract
The architect of Timurid have four systems or sets of proportions that could have combined them, but in general, a system had a major role. These systems can easily be equated to musical steps that although they are run by geometric progression, they are repeated. Each system is set based on an integer, but it is balanced by the root of that integer, according to geometric principles. Integers 2, 3, and 5 are each associated with geometric shapes determining the other elements of the scale. It was indeed Farabi who could discover the kinship of architecture with music, and then it was discussed by Bolatov. The nature of this system is well illustrated according to Farabi stating that the side of square and sector of circle in architecture is used as measuring instruments, and is similar to the theorem in logic and refrain in poetry, as well as poetry rhythms. It is precisely because of such an issue that Bolatov’s view can be accepted. Accordingly, the geometry of the design is not comparable with Western imaginations of proportion, which deals with the repetition of similar or related forms. In addition to its practical value, as an implementation procedure, the Islamic system provided the coordination and harmony for all parts, thereby the entire parts were associated with a single nature, like the relation of the parts of squares, triangles and pentagons with each other. 
Keywords: Applied Geometry, Buildings Abubakr Taybadi, Goharshad Mosque, School of Ghiasieh Khargerd.

Introduction
A feature of the Timurid architecture is the use of geometry, which is manifested in the magnificence and verticality of the Timurid buildings. Also, during this period, exact sciences and geometry significantly developed. These sciences were practically applied in architecture and used as a pattern in the construction of buildings. The application of geometric formulas had a major role in coordinating proportions, balancing and overall balance and its elements, which are the features of the Timurid architecture. After preparing the design, the architect has been entered the practical research stage. Therefore, the following questions are raised in this study: What is the pattern and geometrical ratio used in the design of these buildings? The architect of the Timurid Period which geometrical principles have used in the design of these buildings?

Research Findings
Timurids architects applied all of the geometric systems used since the tenth century, including: 
Rule 1: Square and its derivatives, the most important of which are the diameter of √2 of half and its double, and the side of an octagon (√ 2-1).
Rules 2 and 3: Equilateral triangle and its derivatives, i.e. sides and height (√3/2). Such triangles play a role in dodecagonal figures (the sides are equal,) (2-√3). Sometimes, the geometry of square and equilateral triangle were combined, as it is seen in (√ 2: √3) rectangles whose height is half the generatrix square. Bearer (√3) was often used. The size of this dimension can be drawn by encircling a pentagon and extending its radii.
Rules 6, 5, 4, and 7: A half-square is usually formed by dividing the square of a room into halves, so that by drawing diameters of two half-squares, a square in the center is obtained whose side is 1/ √5. The diameter itself (√5/2) plays a major role especially in determining the heights. Another method to get a rectangle with the same proportions yields a triangle with a ratio of 2:3√5. A common form associated with the half-square was a triangle made of diameters and two sides that could be used to separate the proportional parts of the line 1√5 and (√5-1) 1√5. This was done in a way that an arc was separated along the chord, the radius which was a triangle height, was then entered through this point to the base. These proportions were sometimes used for designs of façades. 
Rules 8 and 9: The √5 of a rectangle or the √5 of orthogonal: using a half-square, the base could be divided in another way, previously known to the Greeks as “moderate limit” which is involved in the construction of the “golden section”. This is done in such a way that an arc with the length of the height along the chord is separated like the previous state, then a secondary arc whose center is smaller in the angle is drawn at the point on the chord. In the point where this arc intercepts the triangle the line is divided into two parts that one is larger {(√5-1)/2} represented by M, and another one is smaller {3-√5/2}} represented by m. The multiples of this section are usually used in the design of interior and exterior façades and many other spaces. A number of decreasing triangles were applied in the same way as used for the diameter of the minarets {2 / (√5 3-7); 4 / √53-7) ...}. 
Rule 10: A decagon encircled in a circle with a radius of 2 has a side equal to √5-1. The golden rectangular was made by adding unit 1 to the larger part M {1: 2 / (√5+1)}. Using the half-square as a base, a rectangle can be easily drawn.
 
Conclosion
Abubakr Taybadi’s Tomb: The use of the rules 2 and 3, i.e. the equilateral triangle and its derivatives, like in the height of the triangle. The use of rule 5 of half-square, i.e. √5 and its derivatives and the rule 9, namely, √5 of the rectangle. The use of rule 4, i.e. half-square. Dividing the square of a room which is divided into halves. The ratio was used in this rule.
Goharshad Mosque: The combined is use of the rule 5 of half-square, namely √5 and its derivatives, and the rule 9, i.e. √5 of rectangle.   
School of Ghiasieh Khargerd: The use of the rule 1, namely √2 and its derivatives such as By analyzing such patterns and the system of proportions used in the construction of Ghiasieh Khargerd School, Goharshad Mosque and Zayn al-Din monument, the present study describes the role of mathematicians and the application of geometry knowledge by architects such as Qavameddin Shirazi in the development process of architecture during the Timurid period.

Abstract
In the Islamic era, the mosque is known as an architectural index and is considered a sacred and blessed place for the Muslims and has a special status and importance. The architecture of the mosque was gradually embellished with decorations, and over the time, it was filled with special concepts that are full of semantic and decorative elements in Islamic architecture that have extremely benefited from the teachings of Qur’an the Muslim Bible. This diamond engraving has been executed with various Quran, prayer, historical and divine names, and sometimes with the techniques of tiling, brickwork and craftsmanship. The analysis of the contents of the inscriptions used in Goharshad and Hakim mosque and also the exploration of the differences and similarities of the inscriptions of the two mosques are the purposes of this article. Which is in response to the following questions: What are the implications in the Qur’an inscriptions of the Hakim Mosque of Isfahan and Goharshad of Mashhad? What is the difference and similarities between the two mosque inscriptions? The study shows that in the inscriptions of Goharshad mosque, Thuluth script is most used among other scripts, and the Cathay bearings, Scrollwork arabesque bearings motifs coincided with the decoration of the building. In Hakim Mosque of Isfahan, the index script in the inscription is Cufic, Sotto script), and most of the inscriptions are on the same script, and also Thuluth script as well as Nasta’liq script are used in the inscription of this collection. Tobeh, Asra ,Jom ‘eh, Dahr  are among the common chapters between these two collections. Although in the Goharshad Mosque of Mashhad and Hakim mosque of Isfahan share similarities in the structure and content of the inscriptions, the decorative enrichment and Quran inscriptions of Goharshad Mosque are more than Hakim Mosque. The research method in this study is descriptive content analysis and collecting the necessary information was through library studies, observation of collected works and fieldwork.
Keywords: The Art of Teimouri, Safavid Art of Goharshad Mosque of Mashhad, Hakim Isfahan Mosque, Quran Inscriptions.

Introduction
After the emergence of Islam, Mosque was considered as main and holy element of Islamic architecture for representing different arts like inscription writing. The Great Mosque of Goharshad was established in Teimouri age to the request of Gohar Shad Aqa, the wife of Shahrokh Teimouri. Hakim Mosque is also a permanent monument form Safavid age adorned with different inscriptions and considerable decorations. In this research two mosques of Goharshad in Mashhad and Hakim in Isfahan about Quran inscriptions will be studied.

Objectives and Necessity
The objective of this research is presenting a fundamental analysis about concepts and meanings of Quran inscriptions in two mosques of Goharshad and Hakim and examining this concepts wit thought and religious backgrounds. The necessity of this research related to content analysis of these works and relationship between them. 

Research questions and hypotheses 
Research questions are: what concepts are presented in Quran inscriptions in two mosques of Goharshad in Mashhad and Hakim in Isfahan in terms of political and religious contexts of two periods? What are the common and different points of inscriptions? Hypotheses are: as the two mentioned monuments are established and inscription writing in two different periods in terms of time and place and ideology and religion in different thinking contexts, probably choosing verses and sayings will have considerable common and different points coming from thinking  and religious orientations of rules of those periods. 

Research Methodology
In this research, it has been attempted to gather information by library studies and field observation, then the data are analyzed by descriptive-analytical method.

Research Background
Goharshad mosque in Mashhad is considered as one of the main monuments of period of Shahrokh Teimouri. It was built by the command of his wife, Goharshad Aqa in vicinity of Holy Shrine of Imam Reza. Its architect was Qavm Al-din Shirazi, famous architect in Teimouri Period has not only the responsibility of designing and building, but tile working and mosque decorations. The dome of Goharshad Mosque has been decorated with turquoise color with the glory expression “There is just one God, He is Allah”. Hakim mosque in Isfahan is one of the Iran’s architecture masterpieces in Safavid age, having various Banaee (geometric Kofi) scripts. This mosques architecture, tile working and especially Banaee script in this mosque can be considered among the great works of Safavid period and the age after this period. This Mosque was established in period of Second Shah Abbas by “Hakim Mohammad David” (his doctor).
 This mosque is located in an old neighborhood called “Bab Al-Dasht”. The biggest and most beautiful altar in Hakim Mosque is altar under dome having special decorations. Ekhlas chapter has been used in some locations of Hakim mosque. Hakim mosque and Goharshad mosque have been studied in many articles by researchers individually or comparing with other complexes in other terms. Quran verses are the most important themes used in architecture inscriptions especially in holy monuments. 
 
Analytical examination of inscriptions
In Teimouri period these themes was affected by Sunny religion in the country and emergence of Sufi and Shia Movements and Sufi social circles. In religion inscriptions of Goharshad mosque, verse18 of Toubeh Chapter has been scripted. Verse18 of Toubeh Chapter mentions five features for builders of center of worship: faith in God, faith in doomsday, saying prayers, giving alimony, being modesty in front of Glorious God. 

Conclusion
Examinations of decoration and adornment of the two mentioned monuments indicates this point that in both complex Quran katibehs, divine names, Persian poems and also Kufi manucripts have been used. The theme of these verses is about purity, uniqueness and glory of God. In these verses it has been emphasized on worshipping God, saying prayers, biulding mosques, being honest and faith in Doosday. By studying these katibehs it becomes evident that  for Teymoori Empirs these works have been a device for expressing kingdom styles, but Safavi rulers used it as concepts and religious slogans supporting Imams and their revelation. Among the different points of Katibes of the two metioned monuments, we can point to this matter that in Great Goharshad mosque the Thoulth manuscript in inscription writing of this monument is among the top of other manuscripts, but in Hakim mosque, Banaee script is evident in its inscriotion writing and also in inscriptions of Gorarshad mosque names of Holy Imams was not evident-except the name of Imam Ali (P.B.U.H). While in Hakim mosque- in south gate and north façade- there are inscriptions adoned by His names. Nastaliq script in these mosques has been used for writing inscriotions of Persian poems that this case is among the common aspects of inscription writing in these two mosques.
 Among the other inscription differences between these two mosques is using Mohaghegh script in the form of a mother and child in edge of Maqsoureh gate. About our hypothesis it can be said that most of the inscriptions in Hakim moaque (Quran and Haith) has fouced on the issue of province as one of the most findamental principles of Sia, but in Goharshad mosque the focus has been on uniqueness of God and His instructions.