Van der Waals surface research use of a model showing the van der Waals surfaces of molecules. Related to the title concept are the ideas of a "van der Waals volume", V, and a "van der Waals surface area," abbreviated variously as A, vdWSA, VSA, and WSA. A van der Waals surface area is an abstract conception of the surface area of atoms or molecules from a mathematical estimation, either computing it from first principles or by integrating over a corresponding van der Waals volume. In simplest case, for a spherical monatomic gas, it is simply the computed surface area of a sphere of
Equable shape its surface area is numerically equal to its volume. As with equable shapes in two dimensions, you may find an equable solid, in which the volume is numerically equal to the surface area, by scaling any solid by an appropriate factor. For example a cube with side length six. Equable shape A two-dimensional equable shape (or perfect shape) is one whose area is numerically equal to its perimeter. For example, a right angled triangle with sides 5, 12 and 13 has area and perimeter both have a unitless numerical value of 30. An area cannot be equal to a length