Demonstration of Quadrilateral Area Change

Demonstration of Quadrilateral Area Change
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2017-02-11 06:35
This example demonstrates the change in the area of a quadrilateral. Key mathematical concepts include quadrilaterals, area calculation, and logic. Using GeoGebra commands such as Segment, Circle, Line, Intersect, etc., a dynamic quadrilateral model is constructed. Suitable for middle school and above students to learn geometric transformations and area calculation.

GeoGebra Commands & Parameters

  1. Segment(A, D) → f
  2. Circle(C, f) → e
  3. Line(C, D) → m
  4. Intersect(e, m) → H, I
  5. CircleArc(C, I, H) → p
  6. Point(p) → B
  7. Line(D, B) → g_1
  8. Segment(B, D) → n
  9. Dilate(A, If[0 < a ≤ 1, 1 - a, 0], D) → A'
  10. Segment(A, A') → s
  11. Line(C, s) → c
  12. Segment(D, C) → g
  13. Midpoint(g) → N
  14. Segment(C, B) → h
  15. Segment(B, A) → i
  16. Midpoint(i) → M
  17. Segment(N, M) → j
  18. Segment(A, C) → k
  19. Intersect(k, n) → L
  20. Line(B, f) → l
  21. Line(A, h) → q
  22. Intersect(l, q) → K
  23. Segment(L, K) → r
  24. Slope(j) → m_1
  25. Slope(r) → m_2
  26. Dilate(D, If[1 < a ≤ 2, 2 - a, 0], N) → B'
  27. Segment(D, B') → t
  28. Dilate(N, If[2 < a ≤ 3, 3 - a, 0], C) → F'
  29. Segment(N, F') → b
  30. Rotate(D, If[3 < a ≤ 4, ((a - 3) * π), π], N) → B'_1
  31. Rotate(B', If[3 < a ≤ 4, ((a - 3) * π), π], N) → B''
  32. Intersect(g_1, c) → M_1
  33. Angle(M_1, C, B) → α
  34. Segment(B'_1, B'') → t'
  35. Dilate(D, If[4 < a ≤ 5, 5 - a, 0], C) → B'_2
  36. Vector(D, B'_2) → u
  37. Translate(A, u) → A'_1
  38. Translate(A', u) → A''
  39. Segment(A'_1, A'') → s'
  40. Rotate(A'_1, If[5 < a ≤ 6, ((a - 5) * α), α], C) → K_1
  41. Rotate(A'', If[5 < a ≤ 6, ((a - 5) * α), α], C) → A'''
  42. Segment(K_1, A''') → s''
  43. Dilate(A, If[6 < a ≤ 7, 7 - a, 0], M) → A'_2
  44. Segment(A, A'_2) → d
  45. Dilate(M, If[7 < a ≤ 8, 8 - a, 0], B) → E'
  46. Segment(M, E') → f_1
  47. Rotate(A, If[8 < a ≤ 9, ((a - 8) * π), π], M) → A'_3
  48. Rotate(A'_2, If[8 < a ≤ 9, ((a - 8) * π), π], M) → L_1
  49. Segment(A'_3, L_1) → d'
  50. Polygon(A, D, C, B) → poly1, a_1, b_1, c_1, d_1
  51. Dilate(N, If[9 < a ≤ 10, 10 - a, 0], M) → F'_1
  52. Segment(N, F'_1) → h_1
  53. Circle(C, 5) → e_1
  54. Intersect(e_1, m, 1) → N_1
  55. Ray(C, N_1) → i_1
  56. Intersect(m, q) → O
  57. Segment(D, O) → j_1
  58. Segment(O, N) → k_1
  59. Min(j_1, k_1) → o
  60. Circle(C, (0.25 * o)) → p_1
  61. Intersect(p_1, i_1, 1) → P
  62. Intersect(p_1, s'', 1) → Q
  63. Angle(Q, C, P) → β
  64. Rotate(Q, If[10 < a ≤ 11, ((a - 10) * β), β], C) → Q'
  65. CircleSector(C, Q, Q') → q_1
  66. Dilate(A, If[11 < a ≤ 12, 12 - a, 0], K) → A'_4
  67. Segment(A, A'_4) → l_1
  68. Dilate(C, If[12 < a ≤ 13, 13 - a, 0], O) → C'
  69. Vector(C, C') → v
  70. Translate(q_1, v) → r_1
  71. Intersect(m, l) → R
  72. Line(D, A) → n_1
  73. Circle(D, 5) → s_1
  74. Intersect(s_1, n_1, 1) → S
  75. Ray(D, S) → t_1
  76. Segment(N, R) → f_2
  77. Segment(R, C) → g_2
  78. Min(f_2, g_2) → w
  79. Circle(D, (0.25 * w)) → c_2
  80. Intersect(c_2, t_1, 1) → U
  81. Intersect(c_2, m) → T, V
  82. Angle(T, D, U) → γ
  83. Rotate(T, If[13 < a ≤ 14, ((a - 13) * γ), γ], D) → T'
  84. CircleSector(D, T, T') → d_2
  85. Dilate(D, If[15 < a ≤ 16, 16 - a, 0], R) → B'_3
  86. Vector(D, B'_3) → u_1
  87. Translate(d_2, u_1) → e_2
  88. Dilate(B, If[14 < a ≤ 15, 15 - a, 0], K) → D'
  89. Segment(B, D') → h_2
  90. Intersect(m, r) → W
  91. Circle(W, (0.6 * Distance[W, N])) → k_2
  92. Dilate(A, If[16 < a ≤ 17, 17 - a, 0], L) → A'_5
  93. Dilate(B, If[16 < a ≤ 17, 17 - a, 0], L) → D'_1
  94. Segment(A, A'_5) → i_2
  95. Segment(B, D'_1) → j_2
  96. Line(K, W) → l_2
  97. Intersect(k_2, l_2) → Z, A_1
  98. Intersect(k_2, m) → B_1, C_1
  99. Dilate(L, If[17 < a ≤ 18, 18 - a, 0], D) → G'
  100. Dilate(L, If[17 < a ≤ 18, 18 - a, 0], C) → G'_1
  101. Segment(L, G') → n_2
  102. Segment(L, G'_1) → p_2
  103. Dilate(L, If[18 < a ≤ 19, 19 - a, 0], K) → G'_2
  104. Segment(L, G'_2) → q_2
  105. Angle(A_1, W, B_1) → δ
  106. Rotate(A_1, If[19 < a ≤ 20, ((a - 19) * δ), δ], W) → D_1
  107. CircleSector(W, A_1, D_1) → r_2
  108. Dilate(W, If[20 < a ≤ 21, 21 - a, 0], N) → W'
  109. Vector(W, W') → v_1
  110. Translate(r_2, v_1) → s_2

AI Drawing Prompt Reference

Draw a quadrilateral and dynamically change its shape and size by adjusting parameter a. Start by creating points A, B, C, and D, then construct the quadrilateral using these points. Use circle, line, and intersection commands to create auxiliary lines and points like point B and point N. Apply scaling, rotation, and translation commands to change the quadrilateral's shape and size, observing the area change.
The prompt above was compiled from the original drawing commands and is for reference only.