Omkreds

Omkreds is the length of the boundary of a two-dimensional figure in Danish geometry. In English, the term is perimeter, while the circle’s boundary is often called the circumference. The concept applies to any plane figure, not just circles.

For a circle, the omkreds depends on the radius or diameter. If the circle has radius r, omkreds = 2πr. If it has diameter d, omkreds = πd. The value is proportional to the circle’s size and uses the constant π.

For polygons and other shapes, the omkreds is the sum of the lengths of all boundary sides. For example, a square with side length s has omkreds 4s, and a rectangle with sides a and b has omkreds 2(a + b). An equilateral triangle with side length t has omkreds 3t.

Measurement and calculation: omkreds can be found from given dimensions using formulas, or measured directly with a ruler or measuring tape on real objects. For irregular shapes, the boundary length can be approximated by dividing the figure into simpler parts, adding their omkreds, or using numerical methods.

Relation to area: omkreds describes only the boundary length, while area describes the size of the region inside. Both properties are fundamental in geometry and are used together in problems involving fit, scale, and optimization.

See also: circumference, perimeter, polygon.