Ptolemy's theorem
In Euclidean geometry, Ptolemy's theorem is a relation between the four sides and two diagonals of a cyclic quadrilateral (a quadrilateral whose vertices lie on a common circle). The theorem is named after the Greek astronomer and mathematician Ptolemy (Claudius Ptolemaeus). Ptolemy used the theorem as an aid to creating his table of chords, a trigonometric table that he applied to astronomy. If the quadrilateral is given with its four vertices A, B, C, and D in order, then the theorem states that: AC·BD=AB·CD+BC·AD. This relation may be verbally expressed as follows:
primaryTopic
Ptolemy's theorem
In Euclidean geometry, Ptolemy's theorem is a relation between the four sides and two diagonals of a cyclic quadrilateral (a quadrilateral whose vertices lie on a common circle). The theorem is named after the Greek astronomer and mathematician Ptolemy (Claudius Ptolemaeus). Ptolemy used the theorem as an aid to creating his table of chords, a trigonometric table that he applied to astronomy. If the quadrilateral is given with its four vertices A, B, C, and D in order, then the theorem states that: AC·BD=AB·CD+BC·AD. This relation may be verbally expressed as follows:
has abstract
25بك المحتوى هنا ينقصه الاستشه ...... حاجة للتوسيع. شارك في تحريرها.
@ar
De stelling van Ptolemaeus is ...... gevolg van deze ongelijkheid.
@nl
Der Satz des Ptolemäus (nach C ...... es pythagoreischen Lehrsatzes.
@de
El teorema de Ptolomeo es una ...... verbal de la siguiente forma:
@es
Il Teorema di Tolomeo è un teo ...... 'Almagesto di Claudio Tolomeo.
@it
In Euclidean geometry, Ptolemy ...... can be inscribed in a circle.
@en
Le théorème de Ptolémée est un ...... s calculs liés à l'astronomie.
@fr
O Teorema de Ptolomeu refere-s ...... ir então que , como queríamos.
@pt
Twierdzenie Ptolemeusza – twie ...... ojawia się w dziele Almagest .
@pl
Неравенство Птолемея: Для любы ...... ки ABCD лежат на одной прямой.
@ru
thumbnail
Link from a Wikipage to an external page
Wikipage page ID
Wikipage revision ID
727,017,817
subject
comment
25بك المحتوى هنا ينقصه الاستشه ...... اً لجداء قطري الرباعي الدائري.
@ar
De stelling van Ptolemaeus is ...... gevolg van deze ongelijkheid.
@nl
Der Satz des Ptolemäus (nach C ...... es pythagoreischen Lehrsatzes.
@de
El teorema de Ptolomeo es una ...... verbal de la siguiente forma:
@es
Il Teorema di Tolomeo è un teo ...... 'Almagesto di Claudio Tolomeo.
@it
In Euclidean geometry, Ptolemy ...... verbally expressed as follows:
@en
Le théorème de Ptolémée est un ...... s calculs liés à l'astronomie.
@fr
O Teorema de Ptolomeu refere-s ...... sim, é verdade que , segue que
@pt
Twierdzenie Ptolemeusza – twie ...... ojawia się w dziele Almagest .
@pl
Неравенство Птолемея: Для любы ...... ки ABCD лежат на одной прямой.
@ru
label
Ptolemy's theorem
@en
Satz von Ptolemäus
@de
Stelling van Ptolemaeus
@nl
Teorema de Ptolomeo
@es
Teorema de Ptolomeu
@pt
Teorema di Tolomeo
@it
Théorème de Ptolémée
@fr
Twierdzenie Ptolemeusza
@pl
Неравенство Птолемея
@ru
مبرهنة بطليموس
@ar
