Area of a Trapezoid

Area of a Trapezoid
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2022-09-13 00:59
This example demonstrates the calculation of the area of a trapezoid, involving geometric shapes and area formulas. Key mathematical concepts include polygon area, properties of parallel lines, and geometric construction techniques. Construction involves using GeoGebra commands such as points, line segments, and parallel lines to create trapezoids and compute their areas. Suitable for middle or high school mathematics education to understand area calculations and geometric transformations.

GeoGebra Commands & Parameters

  1. Point(Ray[A, A + (1, 0)]) → B
  2. PointIn(d) → C
  3. Polygon(A, B, C) → t1, f, a, b
  4. OrthogonalLine(C, g) → h
  5. Intersect(g, h) → C_{1}
  6. Point(Ray[C, C + (1, 0)]) → D
  7. Dilate(C, If[0 < c ≤ 1, 1 - c, 0], D) → F'
  8. Dilate(D, If[1 < c ≤ 2, 2 - c, 0], C_{1}) → D'
  9. Rotate(C, If[2 < c ≤ 3, ((c - 2) * pi), pi], D) → F'_{1}
  10. Rotate(F', If[2 < c ≤ 3, ((c - 2) * pi), pi], D) → F''
  11. Angle(C, B, A) → β
  12. Angle(B, A, C) → γ
  13. If(γ ≟ pi / 2, 12, 16) → o
  14. Midpoint(B, D) → E
  15. Polygon(A, B, E, C) → q1, a_1, b_1, e, c_1
  16. Polygon(E, D, C) → t2, c_2, e_1, d_1
  17. Dilate(D, If[0 < c ≤ 1, 1 - c, 0], E) → D'_{1}
  18. Segment(D, D'_{1}) → i
  19. Rotate(D, If[1 < c ≤ 2, ((-(c - 1)) * pi), (-pi)], E) → D'_{2}
  20. Rotate(D'_{1}, If[1 < c ≤ 2, ((c - 1) * pi), pi], E) → F
  21. Segment(D'_{2}, F) → i'
  22. Segment(C, D) → j
  23. Segment(A, C) → k
  24. Dilate(C, If[2 < c ≤ 3, 3 - c, 0], E) → C'
  25. Segment(C, C') → l
  26. Rotate(E, If[4 < c ≤ 5, ((-(c - 4)) * pi), (-pi)], E) → E'
  27. Rotate(D, If[4 < c ≤ 5, ((-(c - 4)) * pi), (-pi)], E) → D'_{3}
  28. Rotate(C, If[4 < c ≤ 5, ((-(c - 4)) * pi), (-pi)], E) → C'_{1}
  29. Polygon(E', D'_{3}, C'_{1}) → t2', c'_{1}, e', d'_{3}
  30. Segment(C'_{1}, D'_{3}) → m
  31. Segment(D'_{3}, E) → n
  32. Segment(C'_{1}, E) → p
  33. Angle(E, C'_{1}, D'_{3}) → α
  34. OrthogonalLine(C, g) → q
  35. Intersect(g, q) → G
  36. Midpoint(C, G) → H
  37. Dilate(C, If[6 < c ≤ 7, 7 - c, 0], H) → C'_{2}
  38. Segment(C, C'_{2}) → r
  39. Dilate(H, If[7 < c ≤ 8, 8 - c, 0], G) → H'
  40. Segment(H, H') → s
  41. Rotate(C, If[8 < c ≤ 9, ((-(c - 8)) * pi), (-pi)], H) → C'_{3}
  42. Rotate(C'_{2}, If[8 < c ≤ 9, ((-(c - 8)) * pi), (-pi)], H) → I
  43. Segment(C'_{3}, I) → r'
  44. Midpoint(k) → J
  45. Dilate(E, If[9 < c ≤ 10, 10 - c, 0], H) → E'_{1}
  46. Dilate(J, If[9 < c ≤ 10, 10 - c, 0], H) → J'
  47. Segment(J, J') → t
  48. Segment(E, E'_{1}) → f_1
  49. Polygon(A, C'_{1}, E, J) → q2, a_2, g_1, e_2, j_1
  50. Polygon(E, C, J) → t3, j_2, e_3, c_3
  51. Rotate(E, If[11 < c ≤ 12, ((-(c - 11)) * pi), (-pi)], E) → E'_{2}
  52. Rotate(C, If[11 < c ≤ 12, ((-(c - 11)) * pi), (-pi)], E) → C'_{4}
  53. Rotate(J, If[11 < c ≤ 12, ((-(c - 11)) * pi), (-pi)], E) → J'_{1}
  54. Polygon(E'_{2}, C'_{4}, J'_{1}) → t3', j'_{1}, e'_{2}, c'_{4}
  55. Segment(J'_{1}, C'_{4}) → h_1
  56. Segment(C'_{4}, E) → i_1
  57. Segment(E, J'_{1}) → k_1
  58. Segment(A, J) → l_1
  59. Segment(J, C) → m_1
  60. OrthogonalLine(C'_{1}, g) → n_1
  61. Intersect(n_1, p_1) → K
  62. OrthogonalLine(J'_{1}, g) → q_1
  63. Intersect(q_1, g) → L
  64. Dilate(J'_{1}, If[13 < c ≤ 14, 14 - c, 0], L) → M
  65. Segment(J'_{1}, M) → r_1
  66. Dilate(C'_{1}, If[13 < c ≤ 14, 14 - c, 0], K) → N
  67. Segment(C'_{1}, N) → s_1
  68. Polygon(A, L, J'_{1}, J) → q3, a_3, l_2, t_1, j_3
  69. Polygon(L, C'_{1}, J'_{1}) → t4, f_2, l_3, g_2
  70. Dilate(J'_{1}, If[15 < c ≤ 16, 16 - c, 0], J) → O
  71. Vector(J'_{1}, O) → u
  72. Translate(L, u) → L'
  73. Translate(C'_{1}, u) → P
  74. Translate(J'_{1}, u) → Q
  75. Polygon(L', P, Q) → t4', q_2, l', p_2
  76. Segment(P, O) → h_2
  77. Segment(O, L') → i_2
  78. Polygon(A, C'_{1}, K, J) → q4, a_4, k_2, k_3, j_4
  79. Polygon(C'_{1}, J'_{1}, K) → t5, k_4, m_2, n_2
  80. Translate(C'_{1}, u) → R
  81. Translate(J'_{1}, u) → S
  82. Translate(K, u) → K'
  83. Polygon(R, S, K') → t5', k', r_2, s_2
  84. Segment(R, Q) → t_2
  85. Segment(R, K') → b_2

AI Drawing Prompt Reference

Construct a plane figure starting from a given point A and a ray direction to place point B on the ray. Take a line through B (call it g) and choose point C on that line. Draw the line through C perpendicular to g and intersect it with g to obtain C1. From the same ray direction at C, place point D, then form the quadrilateral using A, B, and C as the initial polygon. Create additional points by applying successive dilations and rotations centered at C, D, and later E to get points such as D1 and F-type points, including a rotated copy involving C1 and a segment between C1 and the rotated points. Build the needed supporting triangles/polygons by connecting key vertices with segments, and use midpoints and connected edges to establish the parallel/height relationships used for trapezoid area computation, especially involving C1, D'3, and E-related points.
The prompt above was compiled from the original drawing commands and is for reference only.