X59 –X97
Isogonal & Isotomic Conjugates of Classical Centers
5, 6, 7
3, 4, 5
Kepler
Kimberling
< A B C >: Reference Triangle △ABC
[ A B ]: Sideline AB (Base c = 1)
( A R_b ): Euclid I.22 Guide Circle (A)
( B R_a ): Euclid I.22 Guide Circle (B)
[ B C ]: Sideline BC (Side a)
[ C A ]: Sideline CA (Side b)
circumcircle: Circumcircle of △ABC
incircle: Incircle of △ABC
nine_point_circle: Nine-Point Circle (Euler / Feuerbach Circle)
{ 2, 3 }: Euler Line
A = Vertex A (0.0000, 0.0000)
B = Vertex B (1.0000, 0.0000)
R_b = Radius Point R_b (0.8571, 0.0000)
R_a = Radius Point R_a (0.2857, 0.0000)
C = Vertex C (0.6122, 0.5999)
X_3 = CIRCUMCENTER (0.5000, 0.1021)
X_1 = INCENTER (0.5714, 0.2333)
X_5 = NINE-POINT CENTER (0.5561, 0.2489)
X_2 = CENTROID (0.5374, 0.2000)
X_59 = ISOGONAL CONJUGATE OF X(11) (0.5333, 0.4355)
X_64 = ISOGONAL CONJUGATE OF X(20) (0.5579, 1.5943)
X_65 = ORTHOCENTER OF THE INTOUCH TRIANGLE (0.6041, 0.2933)
X_66 = ISOGONAL CONJUGATE OF X(22) (0.5912, 1.0593)
X_67 = ISOGONAL CONJUGATE OF X(23) (0.7606, -0.2152)
X_68 = PRASOLOV POINT (-0.0535, -0.0055)
X_69 = SYMMEDIAN POINT OF THE ANTICOMPLEMENTARY TRIANGLE (0.4122, 0.0654)
X_70 = ISOGONAL CONJUGATE OF X(26) (0.7750, -1.1016)
X_73 = CROSSPOINT OF INCENTER AND CIRCUMCENTER (0.5487, 0.1428)
X_74 = ISOGONAL CONJUGATE OF EULER INFINITY POINT (0.7484, -0.3437)
X_76 = 3rd BROCARD POINT (0.4567, 0.1388)
X_80 = REFLECTION OF INCENTER IN FEUERBACH POINT (0.8980, -0.1000)
X_84 = ISOGONAL CONJUGATE OF X(40) (0.6071, 0.6816)
X_88 = ISOGONAL CONJUGATE OF X(44) (1.0000, 0.0000)
X_90 = -CROSS CONJUGATE OF X(1) (0.1022, 0.0201)
A
B
C
X3
X1
X5
X2
X59
X64
X65
X66
X67
X68
X69
X70
X73
X74
X76
X80
X84
X88
X90
(a, b, c) = (5, 6, 7) | AB = 1
< A B C >: Reference Triangle △ABC
[ A B ]: Sideline AB (Base c = 1)
( A R_b ): Euclid I.22 Guide Circle (A)
( B R_a ): Euclid I.22 Guide Circle (B)
[ B C ]: Sideline BC (Side a)
[ C A ]: Sideline CA (Side b)
circumcircle: Circumcircle of △ABC
incircle: Incircle of △ABC
nine_point_circle: Nine-Point Circle (Euler / Feuerbach Circle)
{ 2, 3 }: Euler Line
A = Vertex A (0.0000, 0.0000)
B = Vertex B (1.0000, 0.0000)
R_b = Radius Point R_b (0.8000, 0.0000)
R_a = Radius Point R_a (0.4000, 0.0000)
C = Vertex C (0.6400, 0.4800)
X_3 = CIRCUMCENTER (0.5000, 0.0000)
X_1 = INCENTER (0.6000, 0.2000)
X_5 = NINE-POINT CENTER (0.5700, 0.2400)
X_2 = CENTROID (0.5467, 0.1600)
X_59 = ISOGONAL CONJUGATE OF X(11) (0.6000, 0.4000)
X_64 = ISOGONAL CONJUGATE OF X(20) (0.5467, -0.4150)
X_65 = ORTHOCENTER OF THE INTOUCH TRIANGLE (0.6400, 0.2800)
X_66 = ISOGONAL CONJUGATE OF X(22) (0.5467, -0.4150)
X_67 = ISOGONAL CONJUGATE OF X(23) (0.6400, -0.2400)
X_68 = PRASOLOV POINT (-0.0283, 0.1600)
X_69 = SYMMEDIAN POINT OF THE ANTICOMPLEMENTARY TRIANGLE (0.3600, 0.0000)
X_70 = ISOGONAL CONJUGATE OF X(26) (0.6400, -0.4800)
X_73 = CROSSPOINT OF INCENTER AND CIRCUMCENTER (0.5714, 0.0000)
X_74 = ISOGONAL CONJUGATE OF EULER INFINITY POINT (0.6400, -0.4800)
X_76 = 3rd BROCARD POINT (0.4124, 0.0899)
X_80 = REFLECTION OF INCENTER IN FEUERBACH POINT (0.8400, -0.1200)
X_84 = ISOGONAL CONJUGATE OF X(40) (0.6000, 1.2000)
X_88 = ISOGONAL CONJUGATE OF X(44) (1.0000, 0.0000)
X_90 = -CROSS CONJUGATE OF X(1) (2.6000, 0.2000)
A
B
C
X3
X1
X5
X2
X59
X64
X65
X66
X67
X68
X69
X70
X73
X74
X76
X80
X84
X88
X90
(a, b, c) = (3, 4, 5) | AB = 1
< A B C >: Reference Triangle △ABC
[ A B ]: Sideline AB (Base c = 1)
( A R_b ): Euclid I.22 Guide Circle (A)
( B R_a ): Euclid I.22 Guide Circle (B)
[ B C ]: Sideline BC (Side a)
[ C A ]: Sideline CA (Side b)
circumcircle: Circumcircle of △ABC
incircle: Incircle of △ABC
nine_point_circle: Nine-Point Circle (Euler / Feuerbach Circle)
{ 2, 3 }: Euler Line
A = Vertex A (0.0000, 0.0000)
B = Vertex B (1.0000, 0.0000)
R_b = Radius Point R_b (0.7862, 0.0000)
R_a = Radius Point R_a (0.3820, 0.0000)
C = Vertex C (0.6180, 0.4859)
X_3 = CIRCUMCENTER (0.5000, 0.0000)
X_1 = INCENTER (0.5841, 0.2021)
X_5 = NINE-POINT CENTER (0.5590, 0.2429)
X_2 = CENTROID (0.5393, 0.1620)
X_59 = ISOGONAL CONJUGATE OF X(11) (0.5932, 0.4263)
X_64 = ISOGONAL CONJUGATE OF X(20) (0.5393, -0.4130)
X_65 = ORTHOCENTER OF THE INTOUCH TRIANGLE (0.6180, 0.2838)
X_66 = ISOGONAL CONJUGATE OF X(22) (0.5393, -0.4130)
X_67 = ISOGONAL CONJUGATE OF X(23) (0.6180, -0.2429)
X_68 = PRASOLOV POINT (-0.0357, 0.1620)
X_69 = SYMMEDIAN POINT OF THE ANTICOMPLEMENTARY TRIANGLE (0.3820, 0.0000)
X_70 = ISOGONAL CONJUGATE OF X(26) (0.6180, -0.4859)
X_73 = CROSSPOINT OF INCENTER AND CIRCUMCENTER (0.5599, 0.0000)
X_74 = ISOGONAL CONJUGATE OF EULER INFINITY POINT (0.6180, -0.4859)
X_76 = 3rd BROCARD POINT (0.4271, 0.0928)
X_80 = REFLECTION OF INCENTER IN FEUERBACH POINT (0.7953, -0.1425)
X_84 = ISOGONAL CONJUGATE OF X(40) (0.5841, 1.2021)
X_88 = ISOGONAL CONJUGATE OF X(44) (0.9710, -0.0490)
X_90 = -CROSS CONJUGATE OF X(1) (2.9882, 0.2021)
A
B
C
X3
X1
X5
X2
X59
X64
X65
X66
X67
X68
X69
X70
X73
X74
X76
X80
X84
X88
X90
(a, b, c) = (1, √φ, φ) | AB = 1
< A B C >: Reference Triangle △ABC
[ A B ]: Sideline AB (Base c = 1)
( A R_b ): Euclid I.22 Guide Circle (A)
( B R_a ): Euclid I.22 Guide Circle (B)
[ B C ]: Sideline BC (Side a)
[ C A ]: Sideline CA (Side b)
circumcircle: Circumcircle of △ABC
incircle: Incircle of △ABC
nine_point_circle: Nine-Point Circle (Euler / Feuerbach Circle)
{ 2, 3 }: Euler Line
A = Vertex A (0.0000, 0.0000)
B = Vertex B (1.0000, 0.0000)
R_b = Radius Point R_b (0.6923, 0.0000)
R_a = Radius Point R_a (0.5385, 0.0000)
C = Vertex C (0.6331, 0.2801)
X_3 = CIRCUMCENTER (0.5000, -0.2747)
X_1 = INCENTER (0.6154, 0.1300)
X_5 = NINE-POINT CENTER (0.5666, 0.2774)
X_2 = CENTROID (0.5444, 0.0934)
X_59 = ISOGONAL CONJUGATE OF X(11) (0.6302, 0.2712)
X_64 = ISOGONAL CONJUGATE OF X(20) (0.4118, -2.6117)
X_65 = ORTHOCENTER OF THE INTOUCH TRIANGLE (0.6417, 0.2223)
X_66 = ISOGONAL CONJUGATE OF X(22) (0.5104, -0.5592)
X_67 = ISOGONAL CONJUGATE OF X(23) (0.4783, -0.1812)
X_68 = PRASOLOV POINT (0.7351, 0.0696)
X_69 = SYMMEDIAN POINT OF THE ANTICOMPLEMENTARY TRIANGLE (0.3185, -0.0509)
X_70 = ISOGONAL CONJUGATE OF X(26) (0.4574, -0.1394)
X_73 = CROSSPOINT OF INCENTER AND CIRCUMCENTER (0.6250, 0.5094)
X_74 = ISOGONAL CONJUGATE OF EULER INFINITY POINT (0.5025, -0.8451)
X_76 = 3rd BROCARD POINT (0.3495, 0.0360)
X_80 = REFLECTION OF INCENTER IN FEUERBACH POINT (0.6972, -0.1168)
X_84 = ISOGONAL CONJUGATE OF X(40) (0.5404, 5.4577)
X_88 = ISOGONAL CONJUGATE OF X(44) (0.9802, -0.0393)
X_90 = -CROSS CONJUGATE OF X(1) (0.7302, -0.0575)
A
B
C
X3
X1
X5
X2
X59
X64
X65
X66
X67
X68
X69
X70
X73
X74
X76
X80
X84
X88
X90
(a, b, c) = (6, 9, 13) | AB = 1
X59 –X97 (Isogonal & Isotomic Conjugates of Classical Centers ) — 15 representative centers (from 39 in collection) constructed on acute reference triangle \((a, b, c) = (5, 6, 7)\) with unit baseline AB = \(1\) .
X59 is the isogonal conjugate of X11 .
X60 is the isogonal conjugate of X12 .
X61 is the isogonal conjugate of X17 .
X62 is the isogonal conjugate of X18 .
X63 is the isogonal conjugate of X19 .
X64 is the isogonal conjugate of X20 .
X65 is the orthocenter of the intouch triangle .
X66 is the isogonal conjugate of X22 .
X67 is the isogonal conjugate of X23 .
Coordinates for X68 can be obtained easily from the Ceva ratios given his Prasolov’s proof of concurrence.
X69 is the symmedian point of the anticomplementary triangle .
X70 is the isogonal conjugate of X26 .
X71 is the isogonal conjugate of X27 .
X72 is the isogonal conjugate of X28 .
X73 is the crosspoint of incenter and circumcenter.
The tangents at A , B , C to the Neuberg cubic K001 concur in X74
X75 is the isotomic conjugate of incenter.
X76 = anticomplement of X39
X77 is the isogonal conjugate of X33 .
X78 is the isogonal conjugate of X34 .
A construction for X79 appears in Dasari Naga Vijay Krishna , On the Feuerbach Triangle .
X80 is the reflection of incenter in Feuerbach point.
X81 is the cevapoint of incenter and symmedian point.
X82 is the isogonal conjugate of X38 .
X83 is the cevapoint of centroid and symmedian point.
X84 is the isogonal conjugate of X40 .
X85 is the isotomic conjugate of X9 .
X86 is the cevapoint of incenter and centroid.
X87 = isogonal conjugate of X43
X88 is the isogonal conjugate of X44 .
X89 is the isogonal conjugate of X45 .
X90 = isogonal conjugate of X46
X91 is the isogonal conjugate of X47 .
Let LA be the line through X4 parallel to the internal bisector of angle A , and let
X93 is the isogonal conjugate of X49 .
X94 is the isogonal conjugate of X50 .
X95 is the cevapoint of centroid and circumcenter.
X96 is the isogonal conjugate of X52 .
X97 is the isogonal conjugate of X53 .