The lateral surface area of a net is the sum of the areas of all the net's lateral faces, excluding the base and top. A net can be useful for finding the lateral surface area of a prism or pyramid. For example, in a prism, the lateral surface area is the sum of the areas of all the prism's lateral faces. In a pyramid, the lateral surface area is the sum of the areas of all the pyramid's triangular faces, excluding the base.