Rotational Symmetry of Parallelogram by youngcar

Rotational Symmetry of Parallelogram by youngcar
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2016-06-01 10:19
This example demonstrates the rotational symmetry of quadrilaterals. Key mathematical concepts include rotational symmetry and geometric construction. Using GeoGebra commands such as Segment, OrthogonalLine, Point, Intersect, Polygon, Circle, Line, Rotate, Mirror, etc., a parallelogram with rotational symmetry can be constructed. Suitable for middle school and above students to learn geometric transformations.

GeoGebra Commands & Parameters

  1. Segment(A, B) → a
  2. OrthogonalLine(A, a) → b
  3. OrthogonalLine(B, a) → c
  4. Point(b) → C
  5. OrthogonalLine(C, b) → d
  6. Intersect(c, d) → D
  7. Polygon(C, D, B, A) → poly1, c_1, d_1, b_1, a_1
  8. Segment(C, B) → e
  9. Segment(D, A) → f
  10. Intersect(e, f) → E
  11. Polygon(F, G, 4) → poly2, f_1, g, h, i, H, I
  12. Segment(I, G) → j
  13. Segment(H, F) → k
  14. Intersect(j, k) → J
  15. Segment(K, L) → l
  16. Circle(K, L) → p
  17. Point(p) → M
  18. Segment(K, M) → m
  19. Line(M, l) → n
  20. Line(L, m) → q
  21. Intersect(n, q) → N
  22. Segment(M, L) → r
  23. Segment(N, K) → s
  24. Intersect(r, s) → O
  25. Polygon(M, N, L, K) → poly3, m_1, n_1, l_1, k_1
  26. Rotate(C, (-α), E) → C'
  27. Rotate(D, (-α), E) → D'
  28. Rotate(B, (-α), E) → B'
  29. Rotate(A, (-α), E) → A'
  30. Polygon(C', D', B', A') → poly1', c', d', b', a'
  31. Rotate(M, (-α), O) → M'
  32. Rotate(N, (-α), O) → N'
  33. Rotate(L, (-α), O) → L'
  34. Rotate(K, (-α), O) → K'
  35. Polygon(M', N', L', K') → poly3', m', n', l', k'
  36. Segment(P, Q) → t
  37. Segment(P, R) → e_1
  38. Line(Q, e_1) → g_1
  39. Line(R, t) → h_1
  40. Intersect(g_1, h_1) → S
  41. Polygon(P, R, S, Q) → poly4, p_1, r_1, s_1, q_1
  42. Segment(R, Q) → i_1
  43. Segment(S, P) → j_1
  44. Intersect(i_1, j_1) → T
  45. Rotate(P, (-α), T) → P'
  46. Rotate(R, (-α), T) → R'
  47. Rotate(S, (-α), T) → S'
  48. Rotate(Q, (-α), T) → Q'
  49. Polygon(P', R', S', Q') → poly4', p', r', s', q'
  50. Segment(U, V) → t_1
  51. Segment(U, W) → a_2
  52. Line(W, t_1) → b_2
  53. Point(b_2) → Z
  54. Segment(Z, V) → c_2
  55. Polygon(U, V, Z, W) → poly5, u, v, z, w
  56. Segment(W, V) → d_2
  57. Segment(Z, U) → e_2
  58. Intersect(d_2, e_2) → A_1
  59. Rotate(U, (-α), A_1) → U'
  60. Rotate(V, (-α), A_1) → V'
  61. Rotate(Z, (-α), A_1) → Z'
  62. Rotate(W, (-α), A_1) → W'
  63. Polygon(U', V', Z', W') → poly5', u', v', z', w'
  64. Line(B_1, C_1) → f_2
  65. Mirror(D_1, f_2) → E_1
  66. Polygon(D_1, B_1, E_1, C_1) → poly6, d_3, b_3, e_3, c_3
  67. Segment(D_1, E_1) → g_2
  68. Intersect(f_2, g_2) → F_1
  69. Rotate(D_1, (-α), F_1) → G_1
  70. Rotate(B_1, (-α), F_1) → H_1
  71. Rotate(E_1, (-α), F_1) → I_1
  72. Rotate(C_1, (-α), F_1) → J_1
  73. Polygon(G_1, H_1, I_1, J_1) → poly6', g_3, h_2, i_2, j_2
  74. Rotate(poly2, (-α), J) → poly2'
  75. Intersect(p', r') → K_1
  76. Point(e_1) → L_1

AI Drawing Prompt Reference

Draw a parallelogram and demonstrate its rotational symmetry. First, construct the four sides and two diagonals of the parallelogram, then find the intersection point of the diagonals. Rotate the parallelogram around this point by a certain angle to get a new parallelogram. Next, construct new quadrilaterals using the original and rotated vertices, highlighting the relationship between the rotated and original shapes to emphasize rotational symmetry.
The prompt above was compiled from the original drawing commands and is for reference only.