With three-dimensional shapes, the surface area of the object is defined as the total surface area, or the sum of the areas, on every outward surface. (This is different from the lateral surface area, which excludes the base and top of 3-D shapes).

Just like the area of a two-dimensional shape, the surface area definition is measured in square units. Depending on the shape and surface of the object, there are different surface area formulas to keep in mind. We’ll go through the surface area of each shape in turn.