What is the segment called where faces meet on a three-dimensional shape?

In three-dimensional geometry, the segment where two faces of a shape meet is known as an edge. Edges are linear segments that connect the vertices of a solid figure. Each edge represents the intersection of two flat surfaces, or faces, and is an essential characteristic of polyhedra, such as cubes and pyramids. Understanding this concept is crucial for visualizing and working with three-dimensional figures since edges play a significant role in defining the overall structure and shape.

Faces, on the other hand, are the flat surfaces themselves, while vertices are the corners or points where edges meet. A diagonal refers specifically to a segment that connects non-adjacent vertices in polygons, which is not applicable when discussing the intersections of faces in three-dimensional shapes. This understanding helps solidify the foundational concepts of geometry for students studying these shapes.