Respected Reader

As per Ultimate Visual Dictionary, the dome synopsis will follow like this:
A Dome is convex roof. Domes are categorised according to the shapes of both the base and section through the centre of the dome. The base may be circular, square, or polygonal, depending on the plan of the drum(the walls on which the dome rests). The section of a dome may be the same shape as any arch(arches are curved structures used to bridge spans and to support the weight of upper parts of buildings, such as DOMES, as in St.Pauls's Cathedral. There are various types of domes viz *hemispherical*, saucer, polyhedral, onion . Further in Southern India many temples were built for example Virupaksha Temple is having *HEMISPHERICAL DOME* (i.e circular base and semi circular base) SURMOUNTED BY CHATRAVALI.

Thanks and yours truly
medavaram