Final answer:
Roman facades often feature the engaged columns motif, where an arch is surrounded by attached columns. This architectural element can be seen in structures like the Temple of Portunus and the Arch of Titus.
Step-by-step explanation:
Roman facades are often composed with the engaged columns motif, in which an arch is surrounded by a pair of engaged columns. These engaged columns are a defining characteristic of Roman architecture, where the columns are partially embedded in a wall, providing structural support and enhancing the aesthetic appeal of the building. Engaged columns are columns that are attached to the wall instead of being free-standing. This architectural feature can be seen in various Roman structures, such as the Temple of Portunus in Rome and the Arch of Titus.