Area's a quantity expressing the two-dimensional size of a defined part of a surface, typically a region bounded by a closed curve. The term surface area refers to the total area of the exposed surface of a 3-dimensional solid, such as the sum of the areas of the exposed sides of a polyhedron. Area's an important invariant in the differential geometry of surfaces. Units Units for measuring area include: » :area (a) = 100 square meters (m²) :hectare (ha) = 100 ares (a) = 10000 square meters… (More on Area)