Why PQRS is a Rhombus When ABCD is a Rectangle?

Why PQRS is a Rhombus When ABCD is a Rectangle?
Loading the math board and drawing, please wait…
2018-07-23 14:24
This example demonstrates why PQRS becomes a rhombus when ABCD is a rectangle, focusing on the properties of diagonals in rectangles and rhombuses, and the use of coordinate geometry. Key concepts include the bisecting and perpendicular nature of rectangle diagonals, equal side lengths in rhombuses, and GeoGebra commands like Segment, Midpoint, Intersect, and OrthogonalLine. Suitable for high school students and teachers exploring geometric relationships and coordinate methods.

GeoGebra Commands & Parameters

  1. Segment(A, B) → a_1
  2. Segment(B, C) → b_1
  3. Segment(C, D) → c_1
  4. Segment(D, A) → d_1
  5. Midpoint(A, B) → P
  6. Midpoint(B, C) → Q
  7. Midpoint(C, D) → R
  8. Midpoint(D, A) → S
  9. Segment(P, Q) → e_1
  10. Segment(Q, R) → f_1
  11. Segment(R, S) → g_1
  12. Segment(S, P) → h_1
  13. Segment(A, C) → i_1
  14. Segment(B, D) → j_1
  15. Angle(P, S, R) → w_1
  16. Angle(R, Q, P) → y_1
  17. Angle(Q, P, S) → x_1
  18. Angle(S, R, Q) → z_1
  19. Line(A, b_1) → l_1
  20. Line(C, a_1) → l_2
  21. Intersect(l_1, l_2) → D_2
  22. Segment(A, D_2) → d_2
  23. Segment(D_2, C) → c_2
  24. Segment(B, D_2) → j_2
  25. Midpoint(C, D_2) → R_2
  26. Midpoint(A, D_2) → S_2
  27. Segment(Q, R_2) → f_2
  28. Segment(R_2, S_2) → g_2
  29. Segment(S_2, P) → h_2
  30. Angle(P, S_2, R_2) → w_2
  31. Angle(S_2, R_2, Q) → z_2
  32. Angle(R_2, Q, P) → y_2
  33. Angle(Q, P, S_2) → x_2
  34. Circle(B, A) → l_3
  35. Point(l_3) → C_3
  36. Segment(B, C_3) → b_3
  37. Circle(C_3, Segment[C_3, B]) → l_4
  38. Circle(A, Segment[A, B]) → l_5
  39. Intersect(l_4, l_5, 2) → D_3
  40. Segment(C_3, D_3) → c_3
  41. Segment(A, D_3) → d_3
  42. Midpoint(B, C_3) → Q_3
  43. Midpoint(C_3, D_3) → R_3
  44. Midpoint(D_3, A) → S_3
  45. Segment(P, Q_3) → e_3
  46. Segment(S_3, R_3) → g_3
  47. Segment(S_3, P) → h_3
  48. Segment(R_3, Q_3) → f_3
  49. Segment(B, D_3) → j_3
  50. Segment(A, C_3) → i_3
  51. Angle(Q_3, P, S_3) → x_3
  52. Angle(R_3, Q_3, P) → y_3
  53. Angle(S_3, R_3, Q_3) → z_3
  54. Angle(P, S_3, R_3) → w_3
  55. OrthogonalLine(B, a_1) → l_6
  56. Point(l_6) → C_4
  57. Segment(B, C_4) → b_4
  58. OrthogonalLine(C_4, b_4) → l_7
  59. Line(A, b_4) → l_8
  60. Intersect(l_7, l_8) → D_4
  61. Segment(A, D_4) → d_4
  62. Segment(D_4, C_4) → c_4
  63. Midpoint(B, C_4) → Q_4
  64. Midpoint(C_4, D_4) → R_4
  65. Midpoint(D_4, A) → S_4
  66. Segment(P, Q_4) → e_4
  67. Segment(S_4, R_4) → g_4
  68. Segment(S_4, P) → h_4
  69. Segment(R_4, Q_4) → f_4
  70. Segment(A, C_4) → i_4
  71. Segment(B, D_4) → j_4
  72. Angle(P, S_4, R_4) → w_4
  73. Angle(S_4, R_4, Q_4) → z_4
  74. Angle(R_4, Q_4, P) → y_4
  75. Angle(Q_4, P, S_4) → x_4
  76. Circle(B, A) → l_9
  77. OrthogonalLine(B, a_1) → l_{10}
  78. Intersect(l_9, l_{10}, 2) → C_5
  79. Segment(B, C_5) → b_5
  80. OrthogonalLine(C_5, b_5) → l_{11}
  81. OrthogonalLine(A, a_1) → l_{12}
  82. Intersect(l_{11}, l_{12}) → D_5
  83. Segment(C_5, D_5) → c_5
  84. Segment(D_5, A) → d_5
  85. Midpoint(B, C_5) → Q_5
  86. Midpoint(C_5, D_5) → R_5
  87. Midpoint(D_5, A) → S_5
  88. Segment(P, Q_5) → e_5
  89. Segment(S_5, R_5) → g_5
  90. Segment(R_5, Q_5) → f_5
  91. Segment(S_5, P) → h_5
  92. Segment(A, C_5) → i_5
  93. Segment(B, D_5) → j_5
  94. Angle(P, S_5, R_5) → w_5
  95. Angle(Q_5, P, S_5) → x_5
  96. Angle(R_5, Q_5, P) → y_5
  97. Angle(S_5, R_5, Q_5) → z_5

AI Drawing Prompt Reference

Draw a rectangle ABCD, then connect its diagonals AC and BD, which intersect at point D. Next, find the midpoints P, Q, R, and S of sides AB, BC, CD, and DA, respectively. Connect these midpoints to form quadrilateral PQRS. Observe that PQRS is a rhombus because the diagonals AC and BD are perpendicular and bisect each other.
The prompt above was compiled from the original drawing commands and is for reference only.