What is the formula for calculating the surface area of a cuboid?

The formula for calculating the surface area of a cuboid is ( 2(lw) + 2(lh) + 2(wh) ). This formula accounts for all six faces of the cuboid.

To understand this, consider that a cuboid has three pairs of opposite faces: two faces of length ( l ) and height ( h ) (with area ( lh )), two faces of length ( l ) and width ( w ) (with area ( lw )), and two faces of width ( w ) and height ( h ) (with area ( wh )). Since each pair of faces is identical, you multiply the area of each face by 2, leading to the full formula.

In contrast, other choices do not represent the total surface area correctly. For instance, the alternative formulas either provide the area of just one face (option B) or only sum the dimensions of the cuboid (options C and D), which do not consider the areas of the surfaces. Thus, the only valid expression that captures the full surface area is the one you selected.