Quaders

Quaders are geometric solids corresponding to rectangular prisms, also known as cuboids, with six faces that are rectangles and with all interior angles equal to right angles. The term derives from the German Quader; in English, rectangular prism and cuboid are standard, while quader appears mainly in German-language contexts or when discussing cross-language terminology.

A Quader is determined by three orthogonal edge lengths, a, b, and c. Its volume is V = a × b × c, and its surface area is S = 2(ab + bc + ac). The space diagonal has length d = sqrt(a^2 + b^2 + c^2). When a = b = c, it is a cube, a special case of a Quader.

If any of the edge lengths are zero, the figure degenerates into a flat rectangle or line; if faces are not rectangles, the figure is not a Quader—for instance, a general parallelepiped with oblique angles is not a Quader.

Common uses include packaging, architecture, and computer graphics; Quaders also appear as axis-aligned bounding boxes in 3D algorithms.

In summary, Quaders describe the familiar rectangular box shape characterized by orthogonal edges and rectangular faces, with the cube as its most symmetric example.