What Is Surface Area?
Surface area is the total area of every face or curved surface on the outside of a three-dimensional shape, as if you unfolded it flat and measured all the pieces. Different shapes use different formulas — a cube adds up six equal squares, while a sphere or cylinder involves curved surfaces calculated with π.
Example
A cube with 4-inch sides has 6 faces, each 4×4=16 square inches, for a total surface area of 6×16 = 96 square inches.