Längen

Längen is the plural form of the German noun Länge, which denotes the extent of something in one dimension or the measurement of distance along a direction. The term is used across everyday language, science, and mathematics to refer to how long objects are or how far apart points lie. For example, Die Länge eines Tisches describes the length of a table, while die Längen mehrerer Objekte refers to the lengths of several items.

In science and mathematics, length is a scalar quantity that describes how long an object or interval is. In the modern metric system, the base unit for length is the meter (m); commonly used larger or smaller units include kilometer (km), centimeter (cm), millimeter (mm), micrometer (µm), and nanometer (nm). In formulas, the symbol L is often used to denote length, and length carries the SI dimension [L].

Practically, length can be measured with rulers, tapes, calipers, or laser devices. In higher mathematics, the length of a curve is defined as the integral of speed along the path, and the length of a straight line segment is the distance between its endpoints, given by the usual distance formula in Euclidean space.

Historically, German-speaking regions used various local units for length, such as Elle or Zoll, before the widespread adoption of the metric system. Today, Längen are standardized by SI units, and the concept remains central in geometry, physics, engineering, and everyday measurement. The plural form Längen remains common when discussing multiple measured lengths or ranges of length.