Dynamic Proof of SAS Triangle Congruence Theorem by Dan Dale

Dynamic Proof of SAS Triangle Congruence Theorem by Dan Dale
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2019-07-03 20:38
This example dynamically demonstrates the proof of the SAS Triangle Congruence Theorem. It involves core mathematical concepts such as triangle congruence criteria, angles, sides, and rotational transformations. The construction utilizes GeoGebra commands/objects like Circle, Point, Segment, Rotate, Angle, Ray, Intersect, Polygon, CircleSector, Mirror, Line, Dilate, Vector, and Translate. It is suitable for high school mathematics students to learn geometric proofs and for teachers to use in classroom demonstrations.

GeoGebra Commands & Parameters

  1. Circle(A, a) → c
  2. Point(c) → B
  3. Segment(A, B) → f
  4. Circle(A, b) → d
  5. Rotate(B, α, A) → B'
  6. Angle(B, A, B') → β
  7. Ray(A, B') → g
  8. Intersect(d, g, 1) → C
  9. Segment(B, C) → h
  10. Segment(A, C) → i
  11. Min(f, i) → e
  12. Circle(A, (0.25 * e)) → k
  13. Intersect(k, f) → D,
  14. Intersect(k, i) → E,
  15. Polygon(A, B, C) → poly1, c_1, a_1, b_1
  16. CircleSector(A, D, E) → p
  17. Mirror(A, h) → A'
  18. Mirror(B, h) → B'_1
  19. Mirror(C, h) → C'
  20. Polygon(A', B'_1, C') → poly1', c', a', b'_1
  21. Mirror(p, h) → p'
  22. Mirror(A, h) → A'_1
  23. Mirror(B, h) → B'_2
  24. Segment(A'_1, B'_2) → f'
  25. Mirror(A, h) → A'_2
  26. Mirror(C, h) → C'_1
  27. Segment(A'_2, C'_1) → i'
  28. Line(C, B) → j
  29. Point(j) → G
  30. Point(j) → H
  31. Ray(B, H) → l
  32. Ray(C, G) → m
  33. Circle(F, a) → q
  34. Point(q) → I
  35. Segment(F, I) → n
  36. Rotate(I, α, F) → I'
  37. Angle(I, F, I') → γ
  38. Circle(F, b) → r
  39. Ray(F, I') → s
  40. Intersect(r, s, 1) → J
  41. Segment(I, J) → t
  42. Segment(F, J) → f_1
  43. Dilate(B, If[0 < u ≤ 1, 1 - u, 0], I) → B'_3
  44. Vector(B, B'_3) → v
  45. Translate(A, v) → A'_3
  46. Translate(B, v) → B'_4
  47. Segment(A'_3, B'_4) → f'_1
  48. Line(B, n) → g_1
  49. Point(g_1) → K
  50. Angle(K, B, A) → δ
  51. Rotate(A'_3, If[1 < u ≤ 2, ((-(u - 1)) * δ), (-δ)], I) → L
  52. Rotate(B'_4, If[1 < u ≤ 2, ((-(u - 1)) * δ), (-δ)], I) → M
  53. Segment(L, M) → h_1
  54. Dilate(A, If[2 < u ≤ 3, 3 - u, 0], F) → A'_4
  55. Vector(A, A'_4) → w
  56. Translate(A, w) → A'_5
  57. Translate(C, w) → C'_2
  58. Segment(A'_5, C'_2) → i'_1
  59. Line(A, f_1) → i_1
  60. Point(i_1) → N
  61. Angle(N, A, C) → ε
  62. Rotate(A'_5, If[3 < u ≤ 4, ((-(u - 3)) * ε), (-ε)], F) → O
  63. Rotate(C'_2, If[3 < u ≤ 4, ((-(u - 3)) * ε), (-ε)], F) → P
  64. Segment(O, P) → j_1
  65. Translate(p, w) → p'_1
  66. Rotate(p'_1, If[3 < u ≤ 4, ((-(u - 3)) * ε), (-ε)], F) → d_1
  67. Dilate(B, If[4 < u ≤ 5, 5 - u, 0], I) → B'_5
  68. Vector(B, B'_5) → u_1
  69. Translate(A, u_1) → A'_6
  70. Translate(B, u_1) → B'_6
  71. Translate(C, u_1) → C'_3
  72. Polygon(A'_6, B'_6, C'_3) → poly1'_1, c'_3, a'_6, b'_6
  73. Line(B, t) → k_1
  74. Point(k_1) → Q
  75. Angle(Q, B, C) → ζ
  76. Rotate(A'_6, If[5 < u ≤ 6, ((-(u - 5)) * ε), (-ε)], I) → R
  77. Rotate(B'_6, If[5 < u ≤ 6, ((-(u - 5)) * ε), (-ε)], I) → S
  78. Rotate(C'_3, If[5 < u ≤ 6, ((-(u - 5)) * ε), (-ε)], I) → T
  79. Polygon(R, S, T) → poly2, t_1, r_1, s_1
  80. Segment(B, A) → l_1
  81. Segment(A, C) → m_1
  82. Segment(C, B) → n_1
  83. CircleSector(A, D, E) → e_1

AI Drawing Prompt Reference

Create a dynamic demonstration of the SAS Triangle Congruence Theorem. Start by drawing two circles, then construct triangle ABC using rotation and intersection points. Mirror triangle ABC and its related elements. Finally, use a series of rotations, reflections, and transformations to create another triangle A'B'C', ensuring both triangles are congruent.
The prompt above was compiled from the original drawing commands and is for reference only.