# Wikipedia:WikiProject Mathematics/PlanetMath Exchange/51-XX Geometry

This page provides a list of all articles available at PlanetMath in the following topic:

*51-XX Geometry*.

This list will be periodically updated. Each entry in the list has three fields:

*PM*: The first field is the link to the PlanetMath article, along with the article's object ID.*WP*: The second field is either a "guessed" link to a correspondingly named Wikipedia article, produced by the script which generated the list, or one or more manually entered links to the corresponding Wikipedia articles on the subject.*Status*: The third field is the status field, which explains the current status of the entry. The recommended*status*entries are:

Status | means PM article |

N | not needed |

A | adequately covered |

C | copied |

M | merged |

NC | needs copying |

NM | needs merging |

- Please update the WP and Status fields as appropriate.
- if the WP field is correct please remove the qualifier "guess".
- If the corresponding Wikipedia article exists, but the link to it is wrong, please fix the link.
- If you copy or merge an article from PlanetMath, please update the WP and Status fields for that entry.
- If you have any comments, for example, thoughts on how the PlanetMath article compares to the corresponding Wikipedia article(s), please place such comments on a new indented line following the entry. Comments of this kind are very valuable.

Don't forget to include the relevant template if you copy over text or feel like an external link is warranted

- {{planetmath|id=|title=}} for copied over text
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## 51-00 General reference works (handbooks, dictionaries, bibliographies, etc.)[edit]

- PM: alternate proof of parallelogram law, id=3031 -- WP: none -- Status:
**N**

- Paul August ☎ 03:59, 6 May 2006 (UTC)

- PM: angle bisector, id=3623 -- WP: bisector -- Status:
**M**

- Jeekc 15:26, 7 November 2005 (UTC)

- PM: angle sum identity, id=3170 -- WP guess: angle sum identity -- Status:

- Jeekc 15:36, 7 November 2005 (UTC)

- PM: Apollonius theorem, id=146 -- WP: Apollonius theorem -- Status:
**C**

- Oleg Alexandrov (talk) 00:48, 2 April 2006 (UTC)

- PM: Apollonius' circle, id=154 -- WP guess: Apollonius' circle -- Status:

- PM: Brahmagupta's formula, id=153 -- WP: Brahmagupta's formula -- Status:
**A**

- Jeekc 15:31, 7 November 2005 (UTC)

- PM: Brianchon theorem, id=5434 -- WP: Brianchon theorem -- Status:
**A**

- AdamSmithee 09:37, 4 September 2007 (UTC)

- PM: Brocard theorem, id=5483 -- WP guess: Brocard theorem -- Status:

- PM: butterfly theorem, id=3612 -- WP: butterfly theorem -- Status:
**A**

- Jeekc 14:20, 8 January 2006 (UTC)

- PM: Carnot circles, id=5468 -- WP guess: Carnot circles -- Status:

- Jeekc 15:39, 7 November 2005 (UTC)

- PM: chord, id=3586 -- WP: chord (geometry) -- Status:
**A**

- Jeekc 09:42, 8 November 2005 (UTC)

- Jeekc 09:42, 8 November 2005 (UTC)

- PM: complete quadrilateral, id=5469 -- WP guess: complete quadrilateral -- Status:

- PM: concurrent, id=2286 -- WP: concurrency -- Status:
**A**

- Paul August ☎ 04:12, 6 May 2006 (UTC)

- PM: cosines law, id=27 -- WP: law of cosines -- Status:
**A**

- Oleg Alexandrov 02:49, 11 Feb 2005 (UTC) (on behalf of Tokek)

- PM: cyclic quadrilateral, id=150 -- WP: cyclic quadrilateral -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: derivation of cosines law, id=713 -- WP guess: derivation of cosines law -- Status:

- Jeekc 17:15, 27 November 2005 (UTC)

- PM: double angle identity, id=1623 -- WP guess: double angle identity -- Status:

- PM: equilateral triangle, id=143 -- WP guess: equilateral triangle -- Status:

- PM: Erdős-Anning Theorem, id=3814 -- WP guess: Erdős-Anning Theorem -- Status:

- PM: Euler Line, id=155 -- WP: Euler Line -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: fundamental theorem on isogonal lines, id=3407 -- WP guess: fundamental theorem on isogonal lines -- Status:

- PM: Gergonne point, id=1444 -- WP: Gergonne point -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: Gergonne triangle, id=1452 -- WP: Gergonne triangle -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: height, id=645 -- WP: Altitude (triangle) -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: Heron's formula, id=140 -- WP: Heron's formula -- Status:
**A**

- Jeekc 10:59, 8 November 2005 (UTC)

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: hypotenuse, id=1096 -- WP: hypotenuse -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: isogonal conjugate, id=3406 -- WP: isogonal conjugate -- Status:
**NM**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: isosceles triangle, id=149 -- WP: isosceles triangle -- Status:
**A**

- Jeekc 15:43, 9 November 2005 (UTC)

- PM: legs, id=1205 -- WP guess: Leg (geometry) -- Status:
**A**

- Jeekc 15:43, 9 November 2005 (UTC)

- PM: Lemoine circle, id=1449 -- WP guess: Lemoine circle -- Status:

- PM: Lemoine point, id=1448 -- WP: Lemoine point -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: magic circles, id=5704 -- WP guess: magic circles -- Status:

- PM: medial triangle, id=3640 -- WP guess: medial triangle -- Status:

- PM: median, id=142 -- WP: Median (geometry) -- Status:
**A**

- Jeekc 05:55, 9 November 2005 (UTC)

- Jeekc 05:55, 9 November 2005 (UTC)

- PM: Miquel point, id=5470 -- WP guess: Miquel point -- Status:

- PM: Mollweide's equations, id=3160 -- WP guess: Mollweide's equations -- Status:

- PM: Morley's theorem, id=141 -- WP guess: Morley's theorem -- Status:

- PM: Newton's line, id=5471 -- WP guess: Newton's line -- Status:

- PM: Newton-Gauss line, id=5480 -- WP guess: Newton-Gauss line -- Status:

- PM: nine-point circle, id=3641 -- WP: nine-point circle -- Status:
**A**

- Jeekc 04:19, 14 January 2006 (UTC)

- PM: orthic triangle, id=1447 -- WP guess: orthic triangle -- Status:

- PM: orthocenter, id=646 -- WP guess: orthocenter -- Status:

- PM: parallelogram, id=1081 -- WP: parallelogram -- Status:
**A**

- Jeekc 10:15, 8 November 2005 (UTC)

- PM: parallelogram law, id=1082 -- WP: parallelogram law -- Status:
**A**

- Jeekc 10:15, 8 November 2005 (UTC)

- PM: Pascal's mystic hexagram, id=1442 -- WP guess: Pascal's mystic hexagram -- Status:

- PM: pedal triangle, id=3579 -- WP: pedal triangle -- Status:
**A**

- Oleg Alexandrov (talk) 07:56, 3 December 2005 (UTC)

- Jeekc 15:43, 9 November 2005 (UTC)

- PM: proof of Apollonius theorem, id=2968 -- WP guess: proof of Apollonius theorem -- Status:

- PM: proof of Apollonius theorem, id=2967 -- WP guess: proof of Apollonius theorem -- Status:

- PM: proof of Brahmagupta's formula, id=3594 -- WP: Brahmagupta's formula -- Status:
**C**

- Jeekc 10:54, 8 November 2005 (UTC)

- PM: proof of butterfly theorem, id=3613 -- WP guess: proof of butterfly theorem -- Status:
**N**

- Linked to Butterfly theorem. Jeekc 14:37, 8 January 2006 (UTC)

- PM: proof of double angle identity, id=3168 -- WP guess: proof of double angle identity -- Status:

- PM: proof of Erdős-Anning Theorem, id=3828 -- WP guess: proof of Erdős-Anning Theorem -- Status:

- PM: proof of Heron's formula, id=2974 -- WP: Heron's formula -- Status:
**A**

- Jeekc 10:59, 8 November 2005 (UTC)

- PM: proof of Mollweide's equations, id=3161 -- WP guess: proof of Mollweide's equations -- Status:

- PM: proof of parallelogram law, id=2971 -- WP guess: proof of parallelogram law -- Status:

- PM: proof of Ptolemy's inequality, id=3079 -- WP guess: proof of Ptolemy's inequality -- Status:

- PM: proof of Ptolemy's theorem, id=2906 -- WP guess: proof of Ptolemy's theorem -- Status:

- PM: proof of Pythagorean theorem, id=696 -- WP guess: proof of Pythagorean theorem -- Status:

- PM: proof of Pythagorean theorem, id=3130 -- WP guess: proof of Pythagorean theorem -- Status:

- PM: proof of Simson's line, id=3578 -- WP guess: proof of Simson's line -- Status:

- PM: proof of Stewart's theorem, id=2908 -- WP guess: proof of Stewart's theorem -- Status:

- PM: proof of tangents law, id=3632 -- WP guess: proof of tangents law -- Status:

- PM: proof of Thales' theorem, id=3064 -- WP guess: proof of Thales' theorem -- Status:

- PM: Ptolemy's theorem, id=100 -- WP guess: Ptolemy's theorem -- Status:

- PM: Pythagorean theorem, id=98 -- WP: Pythagorean theorem -- Status:
**A**

- Jeekc 15:43, 9 November 2005 (UTC)

- PM: quadrilateral, id=1072 -- WP: quadrilateral -- Status:
**A**

- Jeekc 17:15, 27 November 2005 (UTC)

- Jeekc 17:15, 27 November 2005 (UTC)

- Jeekc 17:15, 27 November 2005 (UTC)

- PM: regular polygon, id=2256 -- WP guess: regular polygon -- Status:

- PM: regular polyhedron, id=2254 -- WP: Platonic solid -- Status:
**A**

- Jeekc 17:15, 27 November 2005 (UTC)

- Jeekc 17:15, 27 November 2005 (UTC)

- PM: right triangle, id=650 -- WP: right triangle -- Status:
**A**

- Jeekc 17:15, 27 November 2005 (UTC)

- PM: Schooten theorem, id=5482 -- WP guess: Schooten theorem -- Status:

- PM: sector of a circle, id=3617 -- WP guess: sector of a circle -- Status:

- PM: Simson's line, id=2277 -- WP: Simson's line -- Status:
**NM**

- The part about the envelope of Simpson's line might need merging. Oleg Alexandrov (talk) 07:56, 3 December 2005 (UTC)

- PM: sines law, id=28 -- WP: law of sines --
**Status:**A

- Tokek 02:49, 11 Feb 2005 (UTC)

- PM: sines law proof, id=757 -- WP guess: sines law proof -- Status:

- PM: sines law proof, id=763 -- WP guess: sines law proof -- Status:

- PM: some proofs for triangle theorems, id=5422 -- WP guess: some proofs for triangle theorems -- Status:

- PM: Stewart's theorem, id=145 -- WP guess: Stewart's theorem -- Status:

- PM: tangents law, id=3631 -- WP guess: tangents law -- Status:

- PM: Thales' theorem, id=3063 -- WP guess: Thales' theorem -- Status:

- Jeekc 15:43, 9 November 2005 (UTC)

- PM: triangle center, id=655 -- WP guess: triangle center -- Status:

- PM: circumcircle, id=6714 -- WP guess: circumcircle -- Status:

- PM: determining when a point is inside a polygon, id=7201 -- WP guess: determining when a point is inside a polygon -- Status:

- PM: non-Euclidean geometry, id=4669 -- WP guess: non-Euclidean geometry -- Status:

- PM: origin, id=6797 -- WP: origin (mathematics) -- Status:

- PM: when is a point inside a triangle, id=7199 -- WP guess: when is a point inside a triangle -- Status:

- PM: n-section of line segment with compass and straightedge, id=9784
^{new!}-- WP guess: n-section of line segment with compass and straightedge -- Status:

- PM: alternative proof of necessity direction of equivalent conditions for triangles (hyperbolic and spherical), id=9539
^{new!}-- WP guess: alternative proof of necessity direction of equivalent conditions for triangles (hyperbolic and spherical) -- Status:

- PM: angles of an isosceles triangle, id=9521
^{new!}-- WP guess: angles of an isosceles triangle -- Status:

- PM: Archimedes' cylinders in cube, id=9704
^{new!}-- WP guess: Archimedes' cylinders in cube -- Status:

- PM: area of regular polygon, id=9501
^{new!}-- WP guess: area of regular polygon -- Status:

- PM: Beltrami-Klein model, id=9409
^{new!}-- WP guess: Beltrami-Klein model -- Status:

- PM: bound on area of right triangle, id=8688
^{new!}-- WP guess: bound on area of right triangle -- Status:

- PM: circle with given center and given radius, id=9563
^{new!}-- WP guess: circle with given center and given radius -- Status:

- PM: cissoid of Diocles, id=9632
^{new!}-- WP guess: cissoid of Diocles -- Status:

- PM: classification of Platonic solids, id=7885
^{new!}-- WP guess: classification of Platonic solids -- Status:

- PM: comparison of common geometries, id=9543
^{new!}-- WP guess: comparison of common geometries -- Status:

- PM: compass and straightedge construction of angle bisector, id=9502
^{new!}-- WP guess: compass and straightedge construction of angle bisector -- Status:

- PM: compass and straightedge construction of center of given circle, id=9556
^{new!}-- WP guess: compass and straightedge construction of center of given circle -- Status:

- PM: compass and straightedge construction of duplicating an angle, id=9548
^{new!}-- WP guess: compass and straightedge construction of duplicating an angle -- Status:

- PM: compass and straightedge construction of geometric mean, id=9581
^{new!}-- WP guess: compass and straightedge construction of geometric mean -- Status:

- PM: compass and straightedge construction of parallel line, id=9506
^{new!}-- WP guess: compass and straightedge construction of parallel line -- Status:

- PM: compass and straightedge construction of perpendicular, id=9562
^{new!}-- WP guess: compass and straightedge construction of perpendicular -- Status:

- PM: compass and straightedge construction of regular pentagon, id=9503
^{new!}-- WP guess: compass and straightedge construction of regular pentagon -- Status:

- PM: compass and straightedge construction of regular triangle, id=9670
^{new!}-- WP guess: compass and straightedge construction of regular triangle -- Status:

- PM: compass and straightedge construction of square, id=9671
^{new!}-- WP guess: compass and straightedge construction of square -- Status:

- PM: construct the center of a given circle, id=9555
^{new!}-- WP guess: construct the center of a given circle -- Status:

- PM: construction of regular 2n-gon from regular n-gon, id=9677
^{new!}-- WP guess: construction of regular 2n-gon from regular n-gon -- Status:

- PM: converse of isosceles triangle theorem, id=9526
^{new!}-- WP guess: converse of isosceles triangle theorem -- Status:

- PM: converting between the Beltrami-Klein model and the Poincaré disc model, id=9431
^{new!}-- WP guess: converting between the Beltrami-Klein model and the Poincaré disc model -- Status:

- PM: converting between the Poincaré disc model and the upper half plane model, id=9432
^{new!}-- WP guess: converting between the Poincaré disc model and the upper half plane model -- Status:

- PM: coordinate way, id=9865
^{new!}-- WP guess: coordinate way -- Status:

- PM: crossed quadrilateral, id=9511
^{new!}-- WP guess: crossed quadrilateral -- Status:

- PM: determining from angles that a triangle is isosceles, id=9528
^{new!}-- WP guess: determining from angles that a triangle is isosceles -- Status:

- PM: differential geometry, id=9558
^{new!}-- WP guess: differential geometry -- Status:

- PM: equiangular polygon, id=9535
^{new!}-- WP guess: equiangular polygon -- Status:

- PM: equiangular triangle, id=9537
^{new!}-- WP guess: equiangular triangle -- Status:

- PM: equilateral polygon, id=9534
^{new!}-- WP guess: equilateral polygon -- Status:

- PM: equivalent conditions for triangles, id=9536
^{new!}-- WP guess: equivalent conditions for triangles -- Status:

- PM: Garfield's proof of Pythagorean theorem, id=9470
^{new!}-- WP guess: Garfield's proof of Pythagorean theorem -- Status:

- PM: generalized Pythagorean theorem, id=9561
^{new!}-- WP guess: generalized Pythagorean theorem -- Status:

- PM: geometric constructions by Euclid, id=9531
^{new!}-- WP guess: geometric constructions by Euclid -- Status:

- PM: great circle, id=8164
^{new!}-- WP guess: great circle -- Status:

- PM: hyperbolic rotation, id=9782
^{new!}-- WP guess: hyperbolic rotation -- Status:

- PM: ideal triangle, id=9447
^{new!}-- WP guess: ideal triangle -- Status:

- PM: index of entries on compass and straightedge constructions, id=9505
^{new!}-- WP guess: index of entries on compass and straightedge constructions -- Status:

- PM: isosceles trapezoid, id=9519
^{new!}-- WP guess: isosceles trapezoid -- Status:

- PM: isosceles triangle theorem, id=9523
^{new!}-- WP guess: isosceles triangle theorem -- Status:

- PM: Lambert quadrilateral, id=9440
^{new!}-- WP guess: Lambert quadrilateral -- Status:

- PM: parallel lines in hyperbolic geometry, id=9411
^{new!}-- WP guess: parallel lines in hyperbolic geometry -- Status:

- PM: perimeter of ellipse, id=9244
^{new!}-- WP guess: perimeter of ellipse -- Status:

- PM: PlanetMath graphics sandbox, id=8856
^{new!}-- WP guess: PlanetMath graphics sandbox -- Status:

- PM: Poincaré disc model, id=9416
^{new!}-- WP guess: Poincaré disc model -- Status:

- PM: Poincaré upper half plane model, id=9418
^{new!}-- WP guess: Poincaré upper half plane model -- Status:

- PM: prismatoid, id=9520
^{new!}-- WP guess: prismatoid -- Status:

- PM: proof of Pythagorean theorem, id=9471
^{new!}-- WP guess: proof of Pythagorean theorem -- Status:

- PM: regular polygon and circles, id=9626
^{new!}-- WP guess: regular polygon and circles -- Status:

- PM: regular triangle, id=9538
^{new!}-- WP guess: regular triangle -- Status:

- PM: right trapezoid, id=9518
^{new!}-- WP guess: right trapezoid -- Status:

- PM: Saccheri quadrilateral, id=9445
^{new!}-- WP guess: Saccheri quadrilateral -- Status:

- PM: scalene triangle, id=8151
^{new!}-- WP guess: scalene triangle -- Status:

- PM: semiperimeter, id=9245
^{new!}-- WP guess: semiperimeter -- Status:

- PM: similarity in geometry, id=9455
^{new!}-- WP guess: similarity in geometry -- Status:

- PM: triangle solving, id=7684
^{new!}-- WP guess: triangle solving -- Status:

- PM: volume as integral, id=9702
^{new!}-- WP guess: volume as integral -- Status:

## 51-01 Instructional exposition (textbooks, tutorial papers, etc.)[edit]

- PM: \operatorname{arc tan} with two arguments, id=7105 -- WP guess: \operatornamearc tan with two arguments -- Status:

- PM: construction of polar coordinates, id=6968 -- WP guess: construction of polar coordinates -- Status:

- PM: coordinate systems, id=6977 -- WP guess: coordinate systems -- Status:

- PM: Euclidean geometry of the plane, id=6962 -- WP guess: Euclidean geometry of the plane -- Status:

- PM: polar coordinates, id=6963 -- WP guess: polar coordinates -- Status:

- PM: polar curve, id=7076 -- WP guess: polar curve -- Status:

- PM: calculator trigonometric functions, id=8168
^{new!}-- WP guess: calculator trigonometric functions -- Status:

- PM: corresponding angles in transversal cutting, id=9588
^{new!}-- WP guess: corresponding angles in transversal cutting -- Status:

- PM: determining signs of trigonometric functions, id=8166
^{new!}-- WP guess: determining signs of trigonometric functions -- Status:

- PM: Euclidean axiom by Hilbert, id=9672
^{new!}-- WP guess: Euclidean axiom by Hilbert -- Status:

- PM: illustration of why SSA may not prove congruence, id=9362
^{new!}-- WP guess: illustration of why SSA may not prove congruence -- Status:

- PM: parallellism in Euclidean plane, id=9533
^{new!}-- WP guess: parallellism in Euclidean plane -- Status:

- PM: parallelogram theorems, id=9598
^{new!}-- WP guess: parallelogram theorems -- Status:

- PM: proof of parallelogram theorems, id=9601
^{new!}-- WP guess: proof of parallelogram theorems -- Status:

- PM: terminal ray, id=8167
^{new!}-- WP guess: terminal ray -- Status:

## 51-03 Historical (must also be assigned at least one classification number from Section 01)[edit]

## 51A05 General theory and projective geometries[edit]

- PM: bisectors theorem, id=6485 -- WP: Angle bisector theorem -- Status:
**NM**

- Jeekc 17:32, 27 November 2005 (UTC)

- PM: Ceva's theorem, id=745 -- WP guess: Ceva's theorem -- Status:

- PM: Generalizations of Ceva theorem, id=5861 -- WP guess: Generalizations of Ceva theorem -- Status:

- PM: Hesse configuration, id=5425 -- WP guess: Hesse configuration -- Status:

- PM: Menelaus' theorem, id=3083 -- WP: Menelaus' theorem -- Status:
**A**

- Jeekc 17:32, 27 November 2005 (UTC)

- PM: Pappus's theorem, id=2328 -- WP: Pappus's hexagon theorem -- Status:
**A**

- Jeekc 17:32, 27 November 2005 (UTC)

- PM: proof of bisectors theorem, id=6487 -- WP guess: proof of bisectors theorem -- Status:
**N**

- Linked to the corresponding page. Jeekc 14:26, 8 January 2006 (UTC)

- PM: proof of bisectors theorem, id=6488 -- WP guess: proof of bisectors theorem -- Status:
**N**

- Linked to the corresponding page. Jeekc 14:26, 8 January 2006 (UTC)

- PM: proof of Ceva's theorem, id=2914 -- WP guess: proof of Ceva's theorem -- Status:

- PM: proof of Menelaus' theorem, id=3092 -- WP guess: proof of Menelaus' theorem -- Status:

- PM: proof of Pappus's theorem, id=4509 -- WP guess: proof of Pappus's theorem -- Status:

- PM: proof of Pascal's mystic hexagram, id=4627 -- WP guess: proof of Pascal's mystic hexagram -- Status:

- PM: proof of trigonometric version of Ceva's theorem, id=6484 -- WP guess: proof of trigonometric version of Ceva's theorem -- Status:

- PM: trigonometric version of Ceva's theorem, id=6483 -- WP guess: trigonometric version of Ceva's theorem -- Status:

- PM: (partial) linear space, id=9596
^{new!}-- WP guess: (partial) linear space -- Status:

- PM: central collineations, id=8105
^{new!}-- WP guess: central collineations -- Status:

- PM: circle has one center, id=9591
^{new!}-- WP guess: circle has one center -- Status:

- PM: cotriangular space, id=9597
^{new!}-- WP guess: cotriangular space -- Status:

- PM: fundamental theorem of projective geometry, id=7838
^{new!}-- WP guess: fundamental theorem of projective geometry -- Status:

- PM: perspectivity, id=8082
^{new!}-- WP guess: perspectivity -- Status:

- PM: polarities and forms, id=7986
^{new!}-- WP guess: polarities and forms -- Status:

- PM: projective geometry, id=7843
^{new!}-- WP guess: projective geometry -- Status:

- PM: projectivity, id=7982
^{new!}-- WP guess: projectivity -- Status:

## 51A10 Homomorphism, automorphism and dualities[edit]

## 51A15 Structures with parallelism[edit]

- PM: affine combination, id=8033
^{new!}-- WP guess: affine combination -- Status:

- PM: affine geometry, id=7988
^{new!}-- WP guess: affine geometry -- Status:

## 51A20 Configuration theorems[edit]

## 51A30 Desarguesian and Pappian geometries[edit]

- PM: Desargues' theorem, id=424 -- WP: Desargues' theorem -- Status:
**A**

- Jeekc 14:31, 8 January 2006 (UTC)

- PM: proof of Desargues' theorem, id=4514 -- WP guess: proof of Desargues' theorem -- Status:
**N**

- Linked to Desargues' theorem's page. Jeekc 14:31, 8 January 2006 (UTC)

- PM: Two generalizations of Desargues Theorem, id=5860 -- WP guess: Two generalizations of Desargues Theorem -- Status:

## 51A35 Non-Desarguesian affine and projective planes[edit]

## 51A45 Incidence structures imbeddable into projective geometries[edit]

## 51A99 Miscellaneous[edit]

## 51Axx Linear incidence geometry[edit]

## 51D20 Combinatorial geometries[edit]

- PM: Bertrand's problem, id=8553
^{new!}-- WP guess: Bertrand's problem -- Status:

- PM: circle line picking, id=8587
^{new!}-- WP guess: circle line picking -- Status:

- PM: circumscribe, id=8557
^{new!}-- WP guess: circumscribe -- Status:

- PM: happy ending problem, id=8383
^{new!}-- WP guess: happy ending problem -- Status:

- PM: lazy caterer's sequence, id=8394
^{new!}-- WP guess: lazy caterer's sequence -- Status:

- PM: Motzkin number, id=8455
^{new!}-- WP guess: Motzkin number -- Status:

## 51Dxx Geometric closure systems[edit]

## 51E05 General block designs[edit]

## 51E15 Affine and projective planes[edit]

- PM: projective line, id=5005 -- WP guess: projective line -- Status:

## 51E20 Combinatorial structures in finite projective spaces[edit]

## 51E30 Other finite incidence structures[edit]

## 51E99 Miscellaneous[edit]

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: dodecahedron, id=5947 -- WP: dodecahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: enneacontahedron, id=5939 -- WP guess: enneacontahedron -- Status:

- PM: heptahedron, id=5953 -- WP guess: heptahedron -- Status:

- PM: hexahedron, id=5954 -- WP: hexahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: hexecontahedron, id=5940 -- WP guess: hexecontahedron -- Status:

- PM: icosahedron, id=5945 -- WP: icosahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: icosidodecahedron, id=5942 -- WP: icosidodecahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: icositetrahedron, id=5944 -- WP guess: icositetrahedron -- Status:

- PM: nonahedron, id=5951 -- WP guess: nonahedron -- Status:

- PM: octahedron, id=5952 -- WP: octahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: pentahedron, id=5955 -- WP: pentahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: tetradecahedron, id=5946 -- WP guess: tetradecahedron -- Status:

- PM: tetrahedron, id=5956 -- WP: tetrahedron -- Status:
**NM**

- Need to add the mensuration part. Jeekc 11:04, 4 January 2006 (UTC)

- PM: triacontahedron, id=5943 -- WP: triacontahedron -- Status:
**A**

- Jeekc 11:04, 4 January 2006 (UTC)

- Jeekc 11:04, 4 January 2006 (UTC)

- PM: undecahedron, id=5948 -- WP guess: undecahedron -- Status:

## 51Exx Finite geometry and special incidence structures[edit]

## 51F05 Absolute planes[edit]

- PM: neutral geometry, id=7467 -- WP guess: neutral geometry -- Status:

## 51F10 Absolute spaces[edit]

## 51F20 Congruence and orthogonality[edit]

- PM: congruence axioms, id=7426 -- WP guess: congruence axioms -- Status:

## 51F99 Miscellaneous[edit]

- PM: Weizenbock's Inequality, id=3837 -- WP guess: Weizenbock's Inequality -- Status:

- PM: directed segment, id=6644 -- WP guess: directed segment -- Status:

- PM: compass and straightedge construction of similar triangles, id=9606
^{new!}-- WP guess: compass and straightedge construction of similar triangles -- Status:

## 51Fxx Metric geometry[edit]

## 51G05 Ordered geometries (ordered incidence structures, etc.)[edit]

- PM: betweenness in rays, id=7449 -- WP guess: betweenness in rays -- Status:

- PM: ordered geometry, id=7326 -- WP guess: ordered geometry -- Status:

- PM: Pasch's Theorem, id=7429 -- WP guess: Pasch's Theorem -- Status:

- PM: a line segment has at most one midpoint, id=9637
^{new!}-- WP guess: a line segment has at most one midpoint -- Status:

- PM: betweenness relation, id=9661
^{new!}-- WP guess: betweenness relation -- Status:

- PM: complementary angles, id=9649
^{new!}-- WP guess: complementary angles -- Status:

- PM: linear ordered geometry, id=9678
^{new!}-- WP guess: linear ordered geometry -- Status:

- PM: proof of uniqueness of center of a circle, id=9625
^{new!}-- WP guess: proof of uniqueness of center of a circle -- Status:

- PM: some theorems on strict betweenness relations, id=9666
^{new!}-- WP guess: some theorems on strict betweenness relations -- Status:

- PM: some theorems on the axioms of order, id=9662
^{new!}-- WP guess: some theorems on the axioms of order -- Status:

- PM: strict betweenness relation, id=9665
^{new!}-- WP guess: strict betweenness relation -- Status:

## 51H05 General theory[edit]

## 51Hxx Topological geometry[edit]

## 51K99 Miscellaneous[edit]

- PM: compass and straightedge construction of inverse point, id=9547
^{new!}-- WP guess: compass and straightedge construction of inverse point -- Status:

## 51Kxx Distance geometry[edit]

## 51M04 Elementary problems in Euclidean geometries[edit]

- PM: area of a spherical triangle, id=5841 -- WP guess: area of a spherical triangle -- Status:

- PM: convex angle, id=6456 -- WP guess: convex angle -- Status:

- PM: corollary of Morley's theorem, id=4479 -- WP guess: corollary of Morley's theorem -- Status:

- PM: Napoleon's theorem, id=4538 -- WP guess: Napoleon's theorem -- Status:

- PM: pivot theorem, id=1383 -- WP guess: pivot theorem -- Status:

- PM: proof of Morley's theorem, id=4465 -- WP guess: proof of Morley's theorem -- Status:

- PM: proof of pivot theorem, id=3674 -- WP guess: proof of pivot theorem -- Status:

- PM: Sylvester's theorem, id=4770 -- WP guess: Sylvester's theorem -- Status:

- PM: cone in \mathbb{R}^3, id=7357 -- WP guess: cone in \mathbbR^3 -- Status:

- PM: developable surface, id=7348 -- WP guess: developable surface -- Status:

- PM: ruled surface, id=7347 -- WP guess: ruled surface -- Status:

- PM: circumferential angle is half the corresponding central angle, id=9551
^{new!}-- WP guess: circumferential angle is half the corresponding central angle -- Status:

- PM: Dehn's theorem, id=8422
^{new!}-- WP guess: Dehn's theorem -- Status:

- PM: opposing angles in a cyclic quadrilateral are supplementary, id=9552
^{new!}-- WP guess: opposing angles in a cyclic quadrilateral are supplementary -- Status:

- PM: proof of Dehn's theorem, id=8423
^{new!}-- WP guess: proof of Dehn's theorem -- Status:

- PM: spherical trigonometry, id=9443
^{new!}-- WP guess: spherical trigonometry -- Status:

- PM: surface of revolution, id=9627
^{new!}-- WP guess: surface of revolution -- Status:

- PM: theorems of Euclid, id=9549
^{new!}-- WP guess: theorems of Euclid -- Status:

## 51M05 Euclidean geometries (general) and generalizations[edit]

- PM: area of the n-sphere, id=4495 -- WP guess: area of the n-sphere -- Status:

- PM: homology of the sphere, id=4490 -- WP guess: homology of the sphere -- Status:

- PM: spherical coordinates, id=4491 -- WP guess: spherical coordinates -- Status:

- Jeekc 14:34, 8 January 2006 (UTC)

- PM: volume of the n-sphere, id=4496 -- WP guess: volume of the n-sphere -- Status:

- PM: parallel postulate, id=4668 -- WP guess: parallel postulate -- Status:

- PM: SNCF metric, id=7083 -- WP guess: SNCF metric -- Status:

- PM: cylindrical coordinates, id=9317
^{new!}-- WP guess: cylindrical coordinates -- Status:

## 51M10 Hyperbolic and elliptic geometries (general) and generalizations[edit]

- PM: Lobachevsky's formula, id=5484 -- WP guess: Lobachevsky's formula -- Status:

- PM: AAS is not valid in spherical geometry, id=9541
^{new!}-- WP guess: AAS is not valid in spherical geometry -- Status:

- PM: limiting triangle, id=9408
^{new!}-- WP guess: limiting triangle -- Status:

- PM: proof of AAA (hyperbolic), id=9454
^{new!}-- WP guess: proof of AAA (hyperbolic) -- Status:

## 51M15 Geometric constructions[edit]

- PM: stereographic projection, id=7110 -- WP guess: stereographic projection -- Status:

- PM: perpendicular bisector, id=8652
^{new!}-- WP guess: perpendicular bisector -- Status:

## 51M16 Inequalities and extremum problems[edit]

- PM: Brunn-Minkowski inequality, id=4743 -- WP guess: Brunn-Minkowski inequality -- Status:

- PM: Hadwiger-Finsler inequality, id=3061 -- WP guess: Hadwiger-Finsler inequality -- Status:

- PM: isoperimetric inequality, id=5397 -- WP guess: isoperimetric inequality -- Status:

- PM: proof of Hadwiger-Finsler inequality, id=3062 -- WP guess: proof of Hadwiger-Finsler inequality -- Status:

## 51M20 Polyhedra and polytopes; regular figures, division of spaces[edit]

- PM: polyhedron, id=1627 -- WP guess: polyhedron -- Status:

## 51M25 Length, area and volume[edit]

- PM: area of a polygonal region, id=9290
^{new!}-- WP guess: area of a polygonal region -- Status:

- PM: solid of revolution, id=9685
^{new!}-- WP guess: solid of revolution -- Status:

- PM: volume of ellipsoid, id=9700
^{new!}-- WP guess: volume of ellipsoid -- Status:

- PM: volume of solid of revolution, id=9691
^{new!}-- WP guess: volume of solid of revolution -- Status:

## 51M99 Miscellaneous[edit]

- PM: congruence, id=1467 -- WP guess: congruence -- Status:

- PM: Euler line proof, id=156 -- WP guess: Euler line proof -- Status:

- PM: secant line, id=6512 -- WP guess: secant line -- Status:

- PM: limited tangent, id=6857 -- WP guess: limited tangent -- Status:

- PM: power of point, id=6854 -- WP guess: power of point -- Status:

- PM: proof of triangle incenter, id=9529
^{new!}-- WP guess: proof of triangle incenter -- Status:

## 51Mxx Real and complex geometry[edit]

## 51N05 Descriptive geometry[edit]

- PM: piecewise smooth, id=3236 -- WP guess: piecewise smooth -- Status:

- PM: rectifiable, id=3235 -- WP: rectifiable curve -- Status:
**A**

- WP rectifiable should redirect to the more general notion of rectifiable set linas 17:08, 26 August 2006 (UTC)

- PM: Bézier curve, id=7272 -- WP guess: Bézier curve -- Status:

- PM: integral representation of length of smooth curve, id=7594 -- WP guess: integral representation of length of smooth curve -- Status:

- PM: straight line is shortest curve between two points, id=7595 -- WP guess: straight line is shortest curve between two points -- Status:

- PM: arclength as filtered limit, id=7793
^{new!}-- WP guess: arclength as filtered limit -- Status:

- PM: NURBS curve, id=9499
^{new!}-- WP guess: NURBS curve -- Status:

- PM: NURBS surface, id=9766
^{new!}-- WP guess: NURBS surface -- Status:

- PM: parallel curve, id=9544
^{new!}-- WP guess: parallel curve -- Status:

- PM: properties of parallel curves, id=9571
^{new!}-- WP guess: properties of parallel curves -- Status:

## 51N10 Affine analytic geometry[edit]

- PM: barycentric coordinates, id=8216
^{new!}-- WP guess: barycentric coordinates -- Status:

- PM: relative interior, id=8466
^{new!}-- WP guess: relative interior -- Status:

## 51N15 Projective analytic geometry[edit]

## 51N20 Euclidean analytic geometry[edit]

- PM: Cartesian coordinates, id=6016 -- WP: Cartesian coordinates -- Status:
**A**

- Tompw 12:50, 26 March 2006 (UTC)

- Tompw 12:50, 26 March 2006 (UTC)

- PM: conic section, id=3584 -- WP: conic section -- Status: 'NM

- Tompw 12:50, 26 March 2006 (UTC)

- PM: conjugate hyperbola, id=6241 -- WP guess: conjugate hyperbola -- Status:

- PM: proof of Steiner's theorem, id=4520 -- WP guess: proof of Steiner's theorem -- Status:

- PM: proof of Van Aubel theorem, id=5413 -- WP guess: proof of Van Aubel theorem -- Status:

- PM: proof of Van Aubel's Theorem, id=4736 -- WP guess: proof of Van Aubel's Theorem -- Status:

- Jeekc 04:23, 14 January 2006 (UTC)

- PM: Steiner's theorem, id=3887 -- WP guess: Steiner's theorem -- Status:

- PM: tangent of conic section, id=6008 -- WP guess: tangent of conic section -- Status:

- PM: three theorems on parabolas, id=2958 -- WP guess: three theorems on parabolas -- Status:

- PM: unit hyperbola, id=5996 -- WP guess: unit hyperbola -- Status:

- PM: Van Aubel theorem, id=5412 -- WP guess: Van Aubel theorem -- Status:

- PM: distance from point to a line, id=7248 -- WP guess: distance from point to a line -- Status:

- PM: quadratic surfaces, id=6700 -- WP: Quadric -- Status:

- Tompw 12:50, 26 March 2006 (UTC)

- PM: proof that the slope of a line is well-defined, id=7442 -- WP guess: proof that the slope of a line is well-defined -- Status:
**NM**

- PM: tangent plane of quadratic surface, id=6681 -- WP guess: tangent plane of quadratic surface -- Status:

- PM: angle between two lines, id=9485
^{new!}-- WP guess: angle between two lines -- Status:

- PM: angle between two planes, id=8457
^{new!}-- WP guess: angle between two planes -- Status:

- PM: angle bisector as locus, id=9492
^{new!}-- WP guess: angle bisector as locus -- Status:

- PM: area of a quadrilateral, id=9248
^{new!}-- WP guess: area of a quadrilateral -- Status:

- PM: curve of Agnesi, id=8892
^{new!}-- WP guess: curve of Agnesi -- Status:

- PM: equation of plane, id=9866
^{new!}-- WP guess: equation of plane -- Status:

- PM: line in space, id=9867
^{new!}-- WP guess: line in space -- Status:

- PM: proof of area of a quadrilateral, id=9266
^{new!}-- WP guess: proof of area of a quadrilateral -- Status:

- PM: slope angle, id=9546
^{new!}-- WP guess: slope angle -- Status:

- PM: transition to skew-angled coordinates, id=9472
^{new!}-- WP guess: transition to skew-angled coordinates -- Status:

## 51N25 Analytic geometry with other transformation groups[edit]

## 51N99 Miscellaneous[edit]

- PM: projection of point, id=9475
^{new!}-- WP guess: projection of point -- Status: