faces (Surface)
In geometry, a face is a flat surface that forms part of the boundary of a solid object. Faces are typically polygonal, meaning they can have three or more straight edges. For example, a cube has six square faces, while a pyramid has a triangular base and triangular side faces.
The number and shape of faces help define the type of solid. For instance, a tetrahedron has four triangular faces, while a dodecahedron has twelve pentagonal faces. Understanding faces is essential in fields like architecture and 3D modeling, where the shape and structure of objects are crucial.