Which architectural element refers to the triangular upper part of a building's facade?

The triangular upper part of a building's facade is called a pediment. This architectural feature is typically found above the entrance of classical buildings and serves both decorative and functional purposes. The design of a pediment often incorporates a triangular shape, which can symbolize the stability and permanence of the structure. It is frequently adorned with sculptures or reliefs that contribute to the overall aesthetic of the building.

Pediments are significant in classical architecture, inspired by ancient Greek and Roman designs, where they were used to enhance the grandeur of temples and public structures. This architectural element creates a visually striking silhouette, drawing the eye upward and emphasizing the verticality of the building.

In contrast, the other choices refer to different architectural components. The architrave is the beam that spans across the top of columns, serving as a support for what lies above it. The cornice is the horizontal decorative molding that crowns a building or wall. The frieze is a broad horizontal band, often decorated, that can be found just below the cornice or above the architrave, serving as a transition between these elements. Each of these features plays a unique role in classical architecture but does not specifically refer to the triangular shape defined by a pediment.