Counter Examples of Congruent Triangles

Counter Examples of Congruent Triangles
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2015-10-31 15:12
This applet helps students visualize the triangle congruence postulates (excluding those involving right triangles). It covers key mathematical concepts such as triangle congruence. Using GeoGebra commands like Segment, Angle, Circle, and Point, it dynamically demonstrates the construction of triangles. Suitable for middle school and above students learning geometry.

GeoGebra Commands & Parameters

  1. Segment(C, A) → b
  2. Angle(A, C, B) → γ_c
  3. Segment(B, C) → a_c
  4. Segment(A, B) → c_c
  5. Angle(B, A, C) → α_c
  6. Angle(C, B, A) → β_c
  7. Circle(H, c_c) → k_{cSSA}
  8. Circle(H, a_c) → p_{aSSA}
  9. Point(p_{aSSA}) → I
  10. Point(k_{cSSA}) → J
  11. Circle(I, b) → q_{bSSA}
  12. Segment(H, I) → l
  13. Segment(H, J) → m
  14. Rotate(H, (-γ_c), I) → H'
  15. Angle(H', I, H) → δ
  16. Line(H', I) → d
  17. Point(d) → D
  18. Polygon(C, A, B) → poly1, b_{O}, c_{O}, a_{O}
  19. Polygon(H, J, D, I) → poly2_1, h, j, b_{SSAc}, i
  20. DynamicCoordinates(D, If[Distance[D, J] < 0.13, x(J), x(D)], If[Distance[D, J] < 0.13, y(J), y(D)]) → E
  21. Segment(E, I) → b_{SSA}
  22. Polygon(H, I, E) → poly3, e_1, h_1, i_1
  23. If(poly1 - 1.5 ≤ poly2_1 ≤ poly1 + 1.5 ∧ E ≟ J, true, false) → g
  24. Circle(H_1, c_c) → k_{cSSS}
  25. Circle(H_1, a_c) → p_{aSSS}
  26. Point(p_{aSSS}) → I_1
  27. Point(k_{cSSS}) → J_1
  28. Circle(I_1, b) → q_{bSSS}
  29. Segment(H_1, I_1) → l_1
  30. Segment(H_1, J_1) → m_1
  31. Point(q_{bSSS}) → K_1
  32. Segment(I_1, K_1) → n_1
  33. Segment(B, A) → c
  34. Segment(A, C) → b_c
  35. Segment(B, C) → a
  36. DynamicCoordinates(K_1, If[Distance[J_1, K_1] < 0.13, x(J_1), x(K_1)], If[Distance[K_1, J_1] < 0.13, y(J_1), y(K_1)]) → F
  37. Polygon(J_1, H_1, I_1) → poly4, i_2, j_2, h_2
  38. Point(p_{aSSS}) → G
  39. Segment(H_1, G) → e
  40. Rotate(G, β_c, H_1) → G'
  41. Angle(G, H_1, G') → α
  42. Line(H_1, G') → f
  43. Intersect(k_{cSSA}, f, 2) → K
  44. Segment(G, L) → k
  45. Segment(H_1, K) → n
  46. DynamicCoordinates(L, If[Distance[K, L] < 0.13, x(K), x(L)], If[Distance[L, K] < 0.13, y(K), y(L)]) → M
  47. Polygon(H_1, G, M) → poly2, m_2, h_3, g_1
  48. Point(p_{aSSS}) → N
  49. Rotate(N, β_c, H_1) → N'
  50. Angle(N, H_1, N') → β
  51. Rotate(H_1, α_c, N') → O
  52. Line(H_1, N) → p
  53. Segment(H_1, N) → s
  54. Line(H_1, N') → q
  55. Point(q) → P
  56. Rotate(H_1, α_c, P) → Q
  57. Angle(H_1, P, Q) → γ
  58. Line(P, Q) → r
  59. Segment(H_1, P) → t
  60. Point(r) → R
  61. Segment(P, R) → a_1
  62. DynamicCoordinates(R, If[Distance[N, R] < 0.13, x(N), x(R)], If[Distance[R, N] < 0.13, y(N), y(R)]) → S
  63. Polygon(S, H_1, P) → poly5, p_1, s_1, h_4
  64. Point(p_{aSSA}) → T
  65. Rotate(T, β_c, H_1) → T'
  66. Angle(T, H_1, T') → ε
  67. Rotate(H_1, (-γ_c), T) → U
  68. Angle(U, T, H_1) → ζ
  69. Line(H_1, T') → b_1
  70. Line(U, T) → c_1
  71. Segment(H_1, T) → d_1
  72. Point(c_1) → V
  73. Point(b_1) → W
  74. DynamicCoordinates(W, If[Distance[V, W] < 0.13, x(V), x(W)], If[Distance[V, W] < 0.13, y(V), y(W)]) → Z
  75. Segment(Z, H_1) → f_1
  76. Segment(V, T) → k_1
  77. Polygon(H_1, V, T) → poly6, t_1, h_5, v
  78. Rotate(A_1, β_c, H_1) → B_1
  79. Angle(A_1, H_1, B_1) → η
  80. Line(H_1, B_1) → r_1
  81. Rotate(H_1, (-γ_c), A_1) → C_1
  82. Angle(C_1, A_1, H_1) → θ
  83. Line(C_1, A_1) → a_2
  84. Intersect(r_1, a_2) → D_1
  85. Angle(H_1, D_1, A_1) → ι
  86. Segment(H_1, A_1) → q_1
  87. Segment(D_1, A_1) → b_2
  88. Segment(D_1, H_1) → c_2
  89. Polygon(A_1, H_1, D_1) → poly7, d_2, a_3, h_6
  90. If(a - 0.1 ≤ q_1 ≤ a + 0.1, true, false) → g_2
  91. Polygon(H_1, D_1, A_1) → poly8, a_4, h_7, d_3

AI Drawing Prompt Reference

Draw a triangle ABC, then construct different triangles using SSA, SAS, and SSS conditions to observe their relationships. First, draw triangle ABC, then use the SSA condition to construct a new triangle by rotating and moving points to adjust angles and lengths, ensuring the new triangle is not congruent to the original. Next, use the SAS condition to construct another triangle, adjusting angles and lengths to verify non-congruence. Finally, use the SSS condition to construct a triangle with all sides equal to those of the original, observing if they are congruent.
The prompt above was compiled from the original drawing commands and is for reference only.