Two Special Points of Triangles

Two Special Points of Triangles
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2021-09-24 01:27
This example demonstrates the Isodynamic points of a triangle. Using commands like Midpoint, Circle, Line, and Polygon, it illustrates the concept of Apollonios circle. Suitable for high school geometry learners and math enthusiasts.

GeoGebra Commands & Parameters

  1. Midpoint(B, C) → M_{BC}
  2. Circle(M_{BC}, C) → c_{ab}
  3. Line(B, C) → g_a
  4. Polygon(A, B, C) → d_{ABC}, c, a, b
  5. Midpoint(A, C) → M_{CA}
  6. Circle(M_{CA}, A) → c_{AC}
  7. Mirror(B, c_{AC}) → B'
  8. LineBisector(B', B) → m_B
  9. Mirror(A, c_{ab}) → A'
  10. LineBisector(A, A') → m_{AA'}
  11. Intersect(m_{AA'}, g_a) → M_A
  12. Circle(M_A, A) → c_A
  13. Line(A, C) → g_b
  14. Intersect(m_B, g_b) → M_B
  15. Circle(M_B, B) → c_B
  16. If(IsInRegion[Intersect[c_A, c_B, 1], d_{ABC}], Intersect[c_A, c_B, 2], Intersect[c_A, c_B, 1]) → IP_2
  17. ToComplex(IP_2) → ip_2
  18. Circle(ip_2, 10) → c_{ip2}
  19. ToComplex(Intersect[c_{ip2}, c_B, 1]) → pi_0
  20. Line(A, B) → g_c
  21. Midpoint(B, A) → M_{AB}
  22. Circle(M_{AB}, A) → c_{AB}
  23. Mirror(C, c_{AB}) → C'
  24. LineBisector(C', C) → m_{CC'}
  25. Intersect(m_{CC'}, g_c) → M_C
  26. Circle(M_C, C) → c_C
  27. If(IsInRegion[Intersect[c_A, c_B, 1], d_{ABC}], Intersect[c_A, c_B, 1], Intersect[c_A, c_B, 2]) → IP_1
  28. Intersect(c_B, g_b) → W_b, W'_{1}
  29. Intersect(c_A, g_a) → W_a, W'_{2}
  30. Intersect(c_C, g_c) → W_{2}, W_c
  31. Line(B, W_b) → w_β
  32. Line(A, W_a) → w_α
  33. Line(C, W_{2}) → w'_{1}
  34. Line(B, W'_{1}) → w'_β
  35. Line(A, W'_{2}) → w'_α
  36. Line(C, W_c) → w'_γ
  37. Intersect(w'_β, w_α) → W'_a
  38. Intersect(w'_α, w'_β) → W'_c
  39. Intersect(w_β, w'_α) → W'_b
  40. Angle(B, A, C) → α
  41. Angle(C, B, A) → β
  42. Angle(A, C, B) → γ
  43. Mirror(C, w'_α) → C'_{1}
  44. Mirror(B, w'_α) → B'_{1}
  45. Mirror(C, w'_α) → C'_{2}
  46. Mirror(A, w'_α) → A'_{1}
  47. Segment(C'_{2}, A'_{1}) → b'
  48. Mirror(A, w'_α) → A'_{2}
  49. Mirror(B, w'_α) → B'_{2}
  50. Segment(A'_{2}, B'_{2}) → c'
  51. Mirror(B, w'_α) → B'_{3}
  52. Mirror(C, w'_α) → C'_{3}
  53. Segment(B'_{3}, C'_{3}) → a'
  54. Mirror(g_a, w'_α) → f
  55. Line(C'_{1}, C) → g
  56. Line(B, B'_{1}) → h
  57. Mirror(B, A) → B'_{4}
  58. Mirror(C, A) → C'_{4}
  59. Point(c_A) → A_0
  60. Segment(A_0, B) → i
  61. Segment(A_0, C) → j
  62. Line(A_0, W_a) → k
  63. Angle(B, A_0, W_a) → δ
  64. Angle(W_a, A_0, C) → ε
  65. Segment(IP_2, p_1) → m
  66. Segment(IP_2, p_2) → n
  67. Segment(IP_2, p_3) → p
  68. Segment(IP_2, p_4) → q
  69. Segment(IP_2, p_5) → r
  70. Angle(p_1, IP_2, p_2) → η
  71. Angle(p_2, IP_2, p_3) → θ
  72. Angle(p_3, IP_2, p_4) → ι
  73. Angle(p_4, IP_2, p_5) → κ
  74. Segment(IP_2, pi_0) → l
  75. Angle(pi_0, IP_2, p_1) → ζ
  76. Angle(p_5, IP_2, pi_0) → λ

AI Drawing Prompt Reference

In triangle ABC, first find the midpoint M_BC of BC, and draw a circle c_ab with center M_BC and radius equal to distance from M_BC to C. Then draw the line g_a through B and C. Construct triangle ABC vertices A, B, C, and mark midpoint M_CA and circle c_AC. Mirror point B about circle c_AC to get B', and draw angle bisector m_B between B' and B. Mirror point A about circle c_ab to get A', and draw angle bisector m_AA' between A and A'. Find intersection M_A of m_AA' and g_a, and draw circle c_A with center M_A and radius equal to distance from M_A to A. Draw line g_b through A and C, and find intersection M_B of m_B and g_b, then draw circle c_B with center M_B and radius equal to distance from M_B to B. Determine the isodynamic point IP_2 based on the region of circles c_A and c_B relative to triangle ABC. Convert IP_2 to complex number, draw circle c_ip2 with center IP_2 and radius 10, and find intersection pi_0 of c_ip2 and c_B. Draw line g_c through A and B, and midpoint M_AB of AB, then draw circle c_AB with center M_AB and radius equal to distance from M_AB to A. Mirror point C about c_AB to get C', draw angle bisector m_CC' between C' and C, and find intersection M_C of m_CC' and g_c, then draw circle c_C with center M_C and radius equal to distance from M_C to C. Determine the isodynamic point IP_1 based on the region of circles c_A and c_B relative to triangle ABC. Find intersections of circles c_A, c_B, c_C with lines g_a, g_b, g_c to get points W_a, W_b, W_c. Construct lines w_α, w_β, w_γ through these points, and through mirroring and intersections obtain points W'_a, W'_b, W'_c. Overall, these constructions illustrate the isodynamic points and related geometric relationships in triangle ABC.
The prompt above was compiled from the original drawing commands and is for reference only.