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.
Ring Saint Sergius, Konstantinopel, lan San Vitale, Ravenna, gereja-gereja tipe pusat, ruang ring beten kubah kagedeang antuk nambahang apsidal saking segi kutus.