målegeometri

Målegeometri, or measurement geometry, is a branch of geometry that focuses on quantifying geometric figures and spaces. It deals with determining and deriving the sizes and other measurable properties of shapes and solids. In Norwegian usage, målegeometri is often associated with mensuration, the practical measurement of length, area, volume, and related quantities, rather than with abstract properties alone.

Core quantities include length (linear measures), area (two-dimensional size), volume (three-dimensional size), perimeter, surface area, and angles. These quantities are obtained by direct measurement, by applying geometric formulas, or by using coordinate and analytic methods. For common shapes, standard formulas give area and volume: rectangle area A = lw, triangle A = 1/2 bh, circle area A = πr^2, and 3D volume formulas for prisms, cylinders, pyramids, and spheres. Irregular shapes can be treated by decomposition into known parts or by integration.

Applications include surveying, architecture, construction, manufacturing, land planning, and computer-aided design. Measurement units and conversions are central, consistent with metrology, the science of measurement accuracy and uncertainty. The field addresses error estimation, rounding, and the use of numerical methods to determine measurements for complex forms.

Historically, målegeometri built on practical needs of engineers and surveyors and has connections to older mathematical traditions in geometry. In modern contexts it overlaps with computational geometry and CAD, where coordinates, plans, and simulations require robust measurement concepts.