But since only the lateral faces are counted in surface area (bases are internal or not exposed in separation), only the 6 triangular lateral faces contribute.

Mon, 04 May 2026 04:50:14 +0000

Understanding Surface Area: Why Only the Lateral Faces Matter When calculating surface area, especially for polyhedra like prisms, pyramids, and other geometric solids, it’s essential to understand which faces contribute meaningfully to the total exposed area. A common misconception is that all faces of a figure contribute equally to surface area—specifically, a frequent assumption is that all six faces of a pyramid or similar body count fully. However, in many cases, only the lateral faces—the slanted or vertical sides—contribute to usable surface area, while the bases are rendered internal or unexposed. This distinction arises because bases are often internal or not exposed during separation, making them irrelevant for external surface area measurements. For example, a square pyramid has one square base (the bottom face) and four triangular lateral faces that form the slanting sides. These triangular faces are the only ones directly exposed to the outside environment, hence responsible for the total surface area. The base, lying horizontally or internally, does not contribute to surface area in externally measured values. ### Why Lateral Faces Dominate Surface Area