Isosceles Trapezoid Exploration by Courtney O'Berry

Isosceles Trapezoid Exploration by Courtney O'Berry
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2018-12-04 10:05
This applet allows students to informally discover properties of isosceles trapezoids with initially modifiable dimensions. Key concepts include trapezoid properties, angles, parallel lines, and symmetry. Constructed using commands like Line, Ray, Point, Midpoint, Slope, OrthogonalLine, Mirror, Dilate, Segment, Circle, Intersect, CircleSector, Vector, Translate, Angle, Rotate, Polygon. Ideal for middle school and above, focusing on geometric exploration and dynamic demonstrations.

GeoGebra Commands & Parameters

  1. Line(A, B) → a
  2. Ray(A, B) → b
  3. Point(b) → C
  4. Midpoint(A, C) → D
  5. Line(A, C) → c
  6. Slope(c) → d
  7. OrthogonalLine(D, c) → g
  8. Point(g) → E
  9. Ray(D, E) → h
  10. Point(h) → F
  11. Slope(h) → i
  12. Line(F, c) → l
  13. Point(l) → G
  14. Point(l) → H
  15. Ray(F, G) → m
  16. Ray(F, H) → n
  17. Point(m) → I
  18. Mirror(I, h) → I'
  19. Dilate(A, If[0 < o ≤ 1, 1 - o, 0], C) → A'
  20. Segment(A, A') → p
  21. Dilate(A, If[1 < o ≤ 2, 2 - o, 0], I) → A'_1
  22. Segment(A, A'_1) → q
  23. Segment(A, C) → r
  24. Segment(C, I') → s
  25. Segment(I', I) → t
  26. Segment(I, A) → a_1
  27. Circle(A, (0.2 * Min[a_1, r])) → c_1
  28. Circle(I, (0.2 * Min[a_1, r])) → d_1
  29. Intersect(d_1, a_1, 1) → J
  30. Intersect(d_1, t, 1) → K
  31. Intersect(c_1, r, 1) → L
  32. Intersect(c_1, a_1, 1) → M
  33. CircleSector(A, L, M) → e_1
  34. CircleSector(I, J, K) → f_1
  35. Dilate(I, If[2 < o ≤ 3, 3 - o, 0], I') → I'_1
  36. Segment(I, I'_1) → b_1
  37. Dilate(A, If[3 < o ≤ 4, 4 - o, 0], C) → A'_2
  38. Vector(A, A'_2) → u
  39. Translate(A, u) → A'_3
  40. Translate(A'_1, u) → N
  41. Segment(A'_3, N) → q'
  42. OrthogonalLine(A, r) → g_1
  43. Point(g_1) → O
  44. Angle(I, A, O) → α
  45. Angle(I', C, A) → β
  46. Rotate(A'_3, If[4 < o ≤ 5, (((o - 4) * 2) * α), (2 * α)], C) → P
  47. Rotate(N, If[4 < o ≤ 5, (((o - 4) * 2) * α), (2 * α)], C) → N'
  48. Segment(P, N') → q''
  49. Dilate(A, If[5 < o ≤ 6, 6 - o, 0], C) → A'_4
  50. Vector(A, A'_4) → v
  51. Translate(e_1, v) → h_1
  52. Rotate(h_1, If[6 < o ≤ 7, ((o - 6) * ((2 * α) + β)), (2 * α) + β], C) → k_1
  53. Dilate(I, If[7 < o ≤ 8, 8 - o, 0], I') → I'_2
  54. Vector(I, I'_2) → w
  55. Translate(f_1, w) → p_1
  56. Rotate(p_1, If[8 < o ≤ 9, ((-(o - 8)) * β), (-β)], I') → q_1
  57. Dilate(A, If[9 < o ≤ 10, 10 - o, 0], I') → A'_5
  58. Segment(A, A'_5) → i_1
  59. Dilate(A, If[10 < o ≤ 11, 11 - o, 0], I) → A'_6
  60. Vector(A, A'_6) → u_1
  61. Translate(A, u_1) → A'_7
  62. Translate(A'_5, u_1) → Q
  63. Segment(A'_7, Q) → j_1
  64. Segment(I, C) → l_1
  65. Angle(L, A, I') → γ
  66. Rotate(A'_7, If[11 < o ≤ 12, ((-(o - 11)) * (2 * γ)), (-2 * γ)], I) → R
  67. Rotate(Q, If[11 < o ≤ 12, ((-(o - 11)) * (2 * γ)), (-2 * γ)], I) → Q'
  68. Segment(R, Q') → m_1
  69. Polygon(A, C, I', I) → poly1, a_2, c_2, i', i_2