Area is the measure of a region's size on a surface. The area of a plane region or plane area refers to the area of a shape or planar lamina, while surface area refers to the area of an open surface or the boundary of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat. It is the two-dimensional analogue of the length of a curve or the volume of a solid . Two different regions may have the same area ; by synecdoche, "area" sometimes is used to refer to the region, as in a "polygonal area".

A shape is a graphical representation of an object's form or its external boundary, outline, or external surface; it is distinct from other object properties, such as color, texture, or material type. In geometry, shape excludes information about the object's location, scale, orientation and reflection. A figure is a representation including both shape and size.