Area
Area is a quantity expressing the size of a region of space. Surface area refers to the summation of the exposed sides of an object. Area (Cx2) is the derivative of volume (Cx3). Area is the antiderivative of length (Cx1). In the case of the perfect closed curve in two dimensions, which is the circle, the area is the simple integral of the circumference. Thus, the circumference is 2πr, while the area is πr2.