Ikkeparallell

Ikkeparallell is a Norwegian term used in geometry to describe objects that are not parallel. In Euclidean geometry, two lines in a plane are ikkeparallell if they do not share the same direction; equivalently, their slopes are different. In Cartesian coordinates, two non-vertical lines are ikkeparallell when their slopes differ, and such lines intersect at exactly one point. If two lines in a plane are ikkeparallell, they meet.

In three-dimensional space, two lines can be ikkeparallell even if they do not intersect. In that case they are skew lines, which are not parallel. If two lines in space do intersect, they are ikkeparallell and cross at a single point. The term daher denotes any non-parallel relationship, regardless of whether the lines meet within the same plane.

Opposite to ikkeparallell is parallell, meaning lines that run in the same direction and do not intersect within a plane. The concept is central in elementary and high school geometry in Norwegian-speaking contexts, where ikkeparallell is used to describe the absence of a parallel relationship between lines.

Etymology and usage: ikke is the Norwegian negation for not, and parallell means parallel. The compound is commonly written as a single word in Norwegian, though some style guides allow hyphenation as ikke-parallell. Examples often appear in mathematical explanations, diagrams, and exercises to distinguish non-parallel lines from parallel ones. See also: parallell, line geometry, skew lines.