Pediments are a form of gable in classical architecture, usually of a triangular shape. Pediments are placed above the horizontal structure of the cornice (an elaborated lintel), or entablature if supported by columns.[1] In ancient architecture, a wide and low triangular pediment (the side angles 12.5° to 16°) typically formed the top element of the portico of a Greek temple, a style continued in Roman temples. But large pediments were rare on other types of building before Renaissance architecture.[2] For symmetric designs, it provides a center point and is often used to add grandness to entrances.
The cornice continues round the top of the pediment, as well as below it; the rising sides are often called the "raking cornice".[4] The tympanum is the triangular area within the pediment, which is often decorated with a pedimental sculpture which may be freestanding or a relief sculpture.[5] The tympanum may hold an inscription, or in modern times, a clock face.
The main variant shapes are the "segmental", "curved", or "arch" pediment, where the straight line triangle of the cornice is replaced by a curve making a segment of a circle, the broken pediment where the cornice has a gap at the apex,[6] and the open pediment, with a gap in the cornice along the base. Both triangular and segmental pediments can have "broken" and "open" forms.[7]
Pediments are found in ancient Greek architecture as early as 580 BC, in the archaic Temple of Artemis, Corfu, which was probably one of the first.[8] Pediments return in Renaissance architecture and are then much used in later styles such as Baroque, Neoclassical, and Beaux-Arts architecture, which favoured the segmental variant.[9]