Forms of cupolas
Cupolas are obtained by rotating an arch, except for faceted cupolas which more closely resemble the Dominical vault. A cupola can be semi-circular, segmental, ogival, conical, etc.
Cupolas are circular in plan. They can, however, be used to cover square or rectangular rooms by using pendentives or squinches. Cupolas on pendentives can be used to cover any kind of polygonal shape in plan.
It is possible to combine several cupolas or to combine cupolas with vaults.