Projective harmonic conjugate
In projective geometry, the harmonic conjugate point of an ordered triple of points on the real projective line is defined by the following construction: Given three collinear points A, B, C, let L be a point not lying on their join and let any line through C meet LA, LB at M, N respectively. If AN and BM meet at K, and LK meets AB at D, then D is called the harmonic conjugate of C with respect to A, B. The point D does not depend on what point L is taken initially, nor upon what line through C is used to find M and N. This fact follows from Desargues theorem.
Cayley–Klein metricComplete quadrangleConic sectionCross-ratioDuality (projective geometry)Equal detour pointFoundations of mathematicsG. B. HalstedGalois geometryGino FanoGolden spiralHarmonic (mathematics)Harmonic conjugate (projective)Harmonic construction (geometry)Harmonic divisionHarmonic progression (mathematics)Harmonic quadrupleInvolution (mathematics)Jean-Victor PonceletKarl Georg Christian von StaudtLuis SantalóMabel Minerva YoungMidpointPappus of AlexandriaPolePole and polarProjective Harmonic ConjugatesProjective geometryProjective harmonic conjugatesProjective line over a ringProjective rangeProjectively extended real lineReal projective lineSchwarz triangle functionTernary operationVictor Schlegel
Link from a Wikipage to another Wikipage
primaryTopic
Projective harmonic conjugate
In projective geometry, the harmonic conjugate point of an ordered triple of points on the real projective line is defined by the following construction: Given three collinear points A, B, C, let L be a point not lying on their join and let any line through C meet LA, LB at M, N respectively. If AN and BM meet at K, and LK meets AB at D, then D is called the harmonic conjugate of C with respect to A, B. The point D does not depend on what point L is taken initially, nor upon what line through C is used to find M and N. This fact follows from Desargues theorem.
has abstract
Die harmonische Teilung bezeic ...... Punktepaaren auf einer Gerade.
@de
Em geometria projetiva, o pont ...... armônico de C em relação A, B.
@pt
En geometría proyectiva, se di ...... yección de la figura original.
@es
En géométrie affine, quatre po ...... me quadratique qui la définit.
@fr
In projective geometry, the ha ...... ss-ratio as (A, B; C, D) = −1.
@en
Van vier verschillende punten ...... van de punten gelijk is aan .
@nl
Гармоническая четвёрка точек — ...... ической. В этом случае пишут .
@ru
Гармонійна четвірка точок — че ...... йною. В цьому випадку пишуть .
@uk
Link from a Wikipage to an external page
Wikipage page ID
16,094,600
page length (characters) of wiki page
Wikipage revision ID
965,862,648
Link from a Wikipage to another Wikipage
wikiPageUsesTemplate
subject
comment
Die harmonische Teilung bezeic ...... e obige Gleichung sich auch so
@de
Em geometria projetiva, o pont ...... armônico de C em relação A, B.
@pt
En geometría proyectiva, se di ...... r como: Propiedad fundamental:
@es
En géométrie affine, quatre po ...... rimer qu'un birapport vaut –1.
@fr
In projective geometry, the ha ...... ollows from Desargues theorem.
@en
Van vier verschillende punten ...... van de punten gelijk is aan .
@nl
Гармоническая четвёрка точек — ...... ической. В этом случае пишут .
@ru
Гармонійна четвірка точок — че ...... йною. В цьому випадку пишуть .
@uk
label
Conjugado harmônico projetivo
@pt
Cuaterna armónica
@es
Division harmonique
@fr
Harmonische Teilung
@de
Harmonische ligging
@nl
Projective harmonic conjugate
@en
Гармоническая четвёрка
@ru
Гармонійна четвірка
@uk