Projective Geometry
Feuerbach circle (Euclidean)
empty plane
conic sections
focal points
pencils of conics
dual pencils of conics
polygon
complete quadrangle
conics by points or tangents
conics by points and tangents
pencil of conics
dual pencil of conics
pencil of circles
pencil of horocycles
Desargues's theorem
Pappus's theorem
Pascal's theorem
Brianchon's theorem
three-conics theorem
focal quadrangle
8-point iteration
circumferences
incircles and excircles
circles by points & tangent
circles by point & tangents
nine-point conic (Euclidean)
Feuerbach circle (Euclidean)
gardener's ellipse
directrix of a conic
focus-sharing ellipses
Metric
+++|+++
00+|++0
++−|++−
++0|00+
00+|+00
0+−|+00
−++|−++
00+|+−0
+−+|+−+
elliptic
Euclidean
hyp: Lobachevskian
dual Euclidean
Galilean
dual Minkowskian
hyp: dual Lobachevskian
Minkowskian
hyp: de Sitter
Elementary constructions
draggable points
intersections of lines/cones
midpoints
focal points of a pair of cones
draggable lines
given points/tangent cones
angular/perpendicular bisectors
perpendicular to a line
focal lines of a pair of cones
given points/tangents
singular cone
given family and point/tangent
given focal polar pair
circle given center and periphery
circles given points/tangents
poles/polars to a cone
images under a reflection
tangents of a cone
pencil of cones
dual pencil of cones
polygon given points
customize elements
hide/reveal elements
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