Pendentive

In architecture, a pendentive is a constructional device permitting the placing of a circular dome over a square room or of an elliptical dome over a rectangular room.^[1] The pendentives, which are triangular segments of a sphere, taper to points at the bottom and spread at the top to establish the continuous circular or elliptical base needed for a dome.^[2] In masonry the pendentives thus receive the weight of the dome, concentrating it at the four corners where it can be received by the piers beneath.

Schematic representation of a dome on pendentives.

Prior to the pendentive's development, builders used the device of corbelling or squinches in the corners of a room. Pendentives commonly occurred in Orthodox, Renaissance, and Baroque churches, with a drum with windows often inserted between the pendentives and the dome. The first experimentation with pendentives began with Roman dome construction in the 2nd–3rd century AD,^[3] while full development of the form came in the 6th-century Eastern Roman cathedral, Hagia Sophia, in Constantinople (Istanbul).^[4]

Gallery

• 
  A pendentive, labelled A. Illustration of a church in Nantua
• 
  Formation of a pendentive by Eugène Viollet-le-Duc, 1856
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  Pendentive structure
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  Dome of the Hagia Sophia, Constantinople/Istanbul
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  Vision of St. John on Patmos by Correggio (1520–1522), San Giovanni Evangelista, Parma
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  The attributes of Allah (God) in intrinsic Islamic calligraphy on the pendentives of Çamlıca Mosque, Istanbul, opened in 2019

See also

• History of Italian Renaissance domes
• Spandrel – Space between a curved figure and a rectangular boundary