 In Italy, the eastern projection beyond the transept is usually a shallow chapel or sometimes an apse.. See section below

The ground-plans of the churches show not only the larger parts of the building, developed for Catholic liturgy – the nave, aisles, transept, choir and chapels – but also reveal that each building contains a pattern of regular divisions called "bays".These bays or compartments are square, rectangular and sometimes trapezoidal, and are defined by the positions of the piers, columns and attached shafts that support the arcades and the overhead vaults.While internally the divisions are created by the locations of the vertical members, externally, the bays can be determined by the positions of the buttresses.