Pendentive

A pendentive is an architectural feature used to transition smoothly from a square or polygonal space beneath a dome to the circular base of the dome itself. Imagine a square room with a round dome atop; the pendentives are curved triangles that connect the four corners of the square to the circle of the dome, providing structural support and stability. This design allows builders to erect large, open interior spaces covered by impressive domes, enhancing both the strength and aesthetic appeal of the structure, as seen in many historic churches and mosques.