View source for Ideal point

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''improper point, point at infinity, infinitely-distant point''

A point that completes the plane in order to describe certain geometrical relations and systems. For example, an [[inversion]] is a one-to-one mapping of the Euclidean plane completed by an ideal point; completion of the affine plane by ideal points leads to the concept of a [[projective plane]]. See also [[Infinitely-distant elements]].

[[Category:Geometry]]