At Saint Sergius, Constantinople, and San Vitale, Ravenna, churches of the central type, the space under the dome was enlarged by having apsidal additions made to the octagon.
Daɣ Saint Sergius, Constantinople d San Vitale, Ravenna, egliz tan n iššikil wan ammas edag ehan sider n dome harik s tisiwad n aspse tan ijjanen har Octagon