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Girih Tiles
''Girih'' tiles are a set of five tiles that were used in the creation of Islamic geometric patterns using strapwork (''girih'') for decoration of buildings in Islamic architecture. They have been used since about the year 1200 and their arrangements found significant improvement starting with the Darb-i Imam shrine in Isfahan in Iran built in 1453. Five tiles The five shapes of the tiles, and their Persian names, are: All sides of these figures have the same length, and all their angles are multiples of 36° (π/5 radians). All of them except the pentagon have bilateral (reflection) symmetry through two perpendicular lines. Some have additional symmetries. Specifically, the decagon has tenfold rotational symmetry (rotation by 36°); and the pentagon has fivefold rotational symmetry (rotation by 72°). The emergence of girih tiles By 11th century, the Islamic discovered a new way to construct the “tile mosaic” due to the development of arithmetic calculation and geomet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radian
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. It is defined such that one radian is the angle subtended at the centre of a circle by an Circular arc, arc that is equal in length to the radius. The unit was formerly an SI supplementary unit and is currently a dimensionless unit, dimensionless SI derived unit,: "The CGPM decided to interpret the supplementary units in the SI, namely the radian and the steradian, as dimensionless derived units." defined in the SI as 1 rad = 1 and expressed in terms of the SI base unit metre (m) as . Angles without explicitly specified units are generally assumed to be measured in radians, especially in mathematical writing. Definition One radian is defined as the angle at the center of a circle in a plane that wikt:subtend, subtends an arc whose length equals the radius of the circle. More generally, the magnit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gothic Architecture
Gothic architecture is an architectural style that was prevalent in Europe from the late 12th to the 16th century, during the High Middle Ages, High and Late Middle Ages, surviving into the 17th and 18th centuries in some areas. It evolved from Romanesque architecture and was succeeded by Renaissance architecture. It originated in the Île-de-France and Picardy regions of northern France. The style at the time was sometimes known as ''opus Francigenum'' (); the term ''Gothic'' was first applied contemptuously during the later Renaissance, by those ambitious to revive the Classical architecture, architecture of classical antiquity. The defining design element of Gothic architecture is the Pointed arch (architecture), pointed arch. The use of the pointed arch in turn led to the development of the pointed rib vault and flying buttresses, combined with elaborate tracery and stained glass windows. At the Abbey of Basilica of Saint-Denis, Saint-Denis, near Paris, the choir was rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
