The total area of a square-based pyramid is the sum of its base area and the area of its four triangular lateral faces. Formula: Area = a² + 2 × a × l.

Lateral area is the sum of the areas of all the side faces (the triangles) of the pyramid, excluding the base.

Slant height is the perpendicular distance from the apex of the pyramid down the center of a lateral face to the midpoint of the base edge.