Triangle Folding Construction and Quadratic Equations

Triangle Folding Construction and Quadratic Equations
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2018-02-26 17:56
① This example demonstrates a geometric folding problem involving a triangle, where folding creates new shapes and leads to a quadratic equation for solving unknown lengths or angles. ② Core mathematical concepts include equilateral triangles, angle bisectors, perpendicular bisectors, reflection symmetry, quadratic equations, and the algebraic representation of geometric quantities. ③ Construction details: Based on the construction summary, the GeoGebra commands used include Polygon, Segment, Midpoint, Rotate, CircleArc, Intersect, AngularBisector, OrthogonalLine, Mirror, Circle, and Line. Multiple auxiliary points (E, F, G) and folded images (E', D', G') are created to explore the relationships before and after folding. ④ This is suitable for upper middle school or high school students, particularly for integrating geometry with algebra, and can be used in inquiry-based learning or mathematical modeling activities.

GeoGebra Commands & Parameters

  1. Polygon(A, C, D, B) → vierhoek1, a, c, d, b
  2. Segment((sqrt(2) / 4, 0), (sqrt(2) / 4, 1)) → f
  3. Segment((sqrt(2) / 2, 0), (sqrt(2) / 2, 1)) → g
  4. Segment(((3 * sqrt(2) / 4), 0), ((3 * sqrt(2) / 4), 1)) → h
  5. Midpoint(B, D) → E
  6. Rotate(D, -90°, E) → DD
  7. CircleArc(E, DD, D) → e
  8. Intersect(e, h, 1) → F
  9. CircleArc(E, F, D) → k
  10. AngularBisector(F, E, D) → i
  11. Intersect(i, c) → G
  12. Segment(E, G) → j
  13. Polygon(A, C, G, E, B) → veelhoek1, a_1, c_1, g_1, e_1, b_1
  14. Polygon(E, D, G) → driehoek1, g_2, e_2, d_1
  15. Rotate(E, (((-(s - 1)) * 180))°, g_1) → E'
  16. Rotate(D, (((-(s - 1)) * 180))°, g_1) → D'
  17. Rotate(G, (((-(s - 1)) * 180))°, g_1) → G'
  18. Polygon(E', D', G') → driehoek1', g', e', d'
  19. Polygon(E, F, G) → driehoek2, g_3, e_3, f_1
  20. Segment(E, D) → l
  21. Segment(D, G) → m
  22. OrthogonalLine(F, a_1) → n
  23. Intersect(j, d') → HH
  24. Intersect(j, d') → II
  25. Intersect(n, j) → R
  26. Intersect(n, a_1) → S
  27. Segment(R, S) → p
  28. Segment(F, S) → q
  29. Mirror(F, g) → H
  30. Mirror(G, g) → I
  31. Segment(I, E) → r
  32. CircleArc(E, B, H) → t
  33. Polygon(I, E, B) → driehoek3, b_2, i_1, e_4
  34. Rotate(I, (((s - 3) * 180))°, r) → I'
  35. Rotate(E, (((s - 3) * 180))°, r) → E'_1
  36. Rotate(B, (((s - 3) * 180))°, r) → B'
  37. Polygon(I', E'_1, B') → driehoek3', b', i', e'_1
  38. Polygon(E, I, A, C, G) → veelhoek2, e_5, i_2, a_2, c_2, g_4
  39. Segment(B, E) → h_1
  40. Segment(B, I) → j_1
  41. Mirror(R, g) → TT
  42. Mirror(S, g) → SS
  43. Segment(SS, TT) → k_1
  44. Segment(SS, H) → l_1
  45. Polygon(I, H, E) → driehoek4, e_6, i_3, h_2
  46. Circle(G, C) → p_1
  47. Intersect(d', f_1) → J
  48. Intersect(d', f_1) → K
  49. Intersect(d', f_1) → L
  50. Intersect(d', f_1) → M
  51. Intersect(p_1, f_1) → N,
  52. CircleArc(G, N, C) → q_1
  53. Line(G, F) → m_1
  54. Intersect(m_1, a_2) → O
  55. Segment(O, F) → n_1
  56. Polygon(O, C, G) → driehoek5, g_5, o, c_3
  57. Rotate(O, (((s - 5) * 180))°, c_3) → O'
  58. Rotate(C, (((s - 5) * 180))°, c_3) → C'
  59. Rotate(G, (((s - 5) * 180))°, c_3) → G'_1
  60. Polygon(O', C', G'_1) → driehoek5', g'_1, o', c'
  61. Polygon(I, A, O, G, E) → veelhoek3, i_4, a_3, o_1, g_6, e_7
  62. Mirror(O, n_1) → O'_1
  63. Mirror(C, n_1) → C'_1
  64. Mirror(G, n_1) → G'_2
  65. Polygon(O'_1, C'_1, G'_2) → driehoek5'_1, g'_2, o'_1, c'_1
  66. Mirror(O, g) → O'_2
  67. Mirror(C, g) → C'_2
  68. Mirror(G, g) → G'_3
  69. Polygon(O'_2, C'_2, G'_3) → driehoek5'_2, g'_3, o'_2, c'_2
  70. Rotate(O, (((s - 5) * 180))°, c_3) → O'_3
  71. Rotate(G, (((s - 5) * 180))°, c_3) → G'_4
  72. Rotate(O'_2, (((-(s - 6)) * 180))°, c'_2) → Q
  73. Rotate(G'_3, (((-(s - 6)) * 180))°, c'_2) → U
  74. Intersect(c', o_1) → V
  75. Intersect(c', o_1) → W
  76. Intersect(c', o_1) → Z
  77. Line(I, H) → r_1
  78. Intersect(o_1, r_1) → T
  79. Segment(O, C) → s_1
  80. Segment(C, G) → t_1
  81. Polygon(I, A, O, T) → vierhoek2, i_5, a_4, o_2, t_2
  82. Rotate(I, (((-(s - 7)) * 180))°, t_2) → I'_1
  83. Rotate(A, (((-(s - 7)) * 180))°, t_2) → A'
  84. Rotate(O, (((-(s - 7)) * 180))°, t_2) → O'_4
  85. Rotate(T, (((-(s - 7)) * 180))°, t_2) → T'
  86. Polygon(I, T, G, E) → vierhoek3, i_6, t_3, g_7, e_8
  87. Segment(E, T) → f_2
  88. Segment(T, E) → j_2
  89. Intersect(Segment[O, N], j_2) → A_1
  90. Segment(A_1, E) → k_2
  91. Rotate(I, (((-(s - 7)) * 180))°, i_6) → I'_2
  92. Rotate(A, (((-(s - 7)) * 180))°, i_6) → A'_1
  93. Rotate(O, (((-(s - 7)) * 180))°, i_6) → O'_5
  94. Rotate(T, (((-(s - 7)) * 180))°, i_6) → T'_1
  95. Polygon(I'_2, A'_1, O'_5, T'_1) → vierhoek2', i'_2, a'_1, o'_5, t'_1
  96. Mirror(N, g) → NN
  97. CircleArc(I, A, NN) → d_2
  98. Segment(I, T) → l_2
  99. Intersect(g'_2, l_2) → B_1
  100. Polygon(N, B_1, T, G) → vierhoek4, n_2, b_3, t_4, g_8
  101. Segment(I, A) → m_2
  102. Segment(A, O) → p_2
  103. Midpoint(B, E) → C_1
  104. Midpoint(I, G) → D_1
  105. Midpoint(E, D) → E_1
  106. Mirror(O, l_2) → OO
  107. Mirror(A, l_2) → AA
  108. Polygon(I, T, OO, AA) → vierhoek5, i_7, t_5, oo, aa
  109. Segment(B_1, OO) → s_2
  110. Intersect(i_3, oo) → F_1
  111. Polygon(F_1, OO, E) → driehoek6, e_9, f_3, oo_1
  112. Polygon(E, T, G) → driehoek7, g_9, e_{10}, t_6
  113. Rotate(E, (((-(s - 9)) * 180))°, g) → E'_2
  114. Rotate(T, (((-(s - 9)) * 180))°, g) → T'_2
  115. Rotate(G, (((-(s - 9)) * 180))°, g) → G'_5
  116. Polygon(E'_2, T'_2, G'_5) → driehoek7', g'_5, e'_2, t'_2
  117. Segment(E, T) → h_3
  118. Segment(OO, E) → j_3
  119. Polygon(I, T, E) → driehoek8, e_{11}, i_8, t_7
  120. OrthogonalLine(I, e_6) → q_2
  121. OrthogonalLine(G, e_3) → r_2
  122. Intersect(r_2, q_2) → G_1
  123. CircleArc(G_1, I, G) → d_3

AI Drawing Prompt Reference

Draw an equilateral triangle and construct a geometric folding problem within it. Start by drawing three segments from one vertex to represent the new shapes formed after folding. Find the midpoints of these segments and use them to draw arcs and angle bisectors. Locate the intersection points and construct new triangles. Then, rotate and mirror the new triangles to simulate the folding process. Finally, draw auxiliary lines and shapes to illustrate the relationships between the folded and unfolded forms and the algebraic representation of geometric quantities.
The prompt above was compiled from the original drawing commands and is for reference only.