Quader

Quader is a term with several related uses in German and related languages. In German, the word literally means a block or a solid piece of material, and it is used in everyday language as well as in technical contexts to refer to a solid with defined faces.

In geometry, a Quader denotes a six-faced polyhedron with quadrilateral faces. The most common instance is the rectangular prism, also known as a cuboid, in which opposite faces are parallel and congruent and the edges meet at right angles. If the three edge lengths are a, b, and c, the volume is a times b times c, and the surface area is two times (ab plus bc plus ac). The space diagonal has length equal to the square root of (a squared plus b squared plus c squared). If all edges are equal, the figure becomes a cube; if faces are rectangles but edges are not all perpendicular, it is still a general Quader but not a cube.

Beyond mathematics, Quader also appears as a general term for a block in construction or design, describing modular solid units used in various building or artistic applications.

As a surname, Quader is found among individuals in German-speaking communities and among people with connections to those regions. It may appear in different transliterations or adaptations in diaspora populations.

In summary, Quader can refer to a geometric six-faced solid, a commonly used word for a block, or a personal surname, with distinctions based on context.