The Caliph al-Hafiz ( 1129 1149 ) made significant further changes, adding a fourth arcade with keel arches, and a dome with elaborate carved stucco decorations in front of the transept.
2.
Although heavily influenced by architecture from Mesopotamia and Byzantium, the Fatimids introduced or developed unique features such as the four-centred keel arch and the squinch, connecting square interior volumes to the dome.
परिभाषा
a pointed arch having an S-shape on both sides पर्याय: ogee arch,