Exploring Quadrilateral Area

Exploring Quadrilateral Area
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2017-08-18 04:32
This example demonstrates how to explore the area of a quadrilateral through geometric construction. Key mathematical concepts include polygons, angles, transformations, and slider animation. Using GeoGebra commands such as Line, Polygon, Rotate, and Mirror, dynamic construction and observation of quadrilateral changes are achieved. Suitable for middle school and above students and teachers.

GeoGebra Commands & Parameters

  1. Line(A, B) → a
  2. OrthogonalLine(A, a) → b
  3. Point(b) → C
  4. Line(C, a) → c
  5. OrthogonalLine(B, a) → d
  6. Intersect(c, d) → D
  7. Segment(A, B) → e
  8. Point(e) → E
  9. Segment(E, C) → f
  10. Segment(E, D) → g
  11. Midpoint(f) → F
  12. Midpoint(g) → G
  13. Semicircle(E, D) → h
  14. OrthogonalLine(E, e) → i
  15. Intersect(c, i) → H
  16. Semicircle(B, H) → k
  17. Semicircle(D, E) → p_1
  18. Semicircle(H, A) → q
  19. Semicircle(C, E) → r
  20. Semicircle(E, C) → s
  21. Rotate(E, -α, G) → E'
  22. Angle(E', G, E) → β
  23. Rotate(B, -α, G) → B'
  24. Angle(B', G, B) → γ
  25. Rotate(D, -α, G) → D'
  26. Angle(D', G, D) → δ
  27. Polygon(E', B', D') → poly1, d', e', b'
  28. Rotate(A, α, F) → A'
  29. Angle(A, F, A') → ε
  30. Rotate(E, α, F) → E'_1
  31. Angle(E, F, E'_1) → ζ
  32. Rotate(C, α, F) → C'
  33. Angle(C, F, C') → η
  34. Polygon(A', C', E'_1) → poly2, e'_1, a', c'
  35. Midpoint(e) → I
  36. Midpoint(A, C) → J
  37. Midpoint(C, D) → K
  38. Midpoint(B, D) → L
  39. Polygon(J, I, L, K) → poly3, j_1, i_1, l, k_1
  40. Midpoint(j_1) → M
  41. Midpoint(i_1) → N
  42. Midpoint(l) → O
  43. Midpoint(k_1) → P
  44. Rotate(J, α, P) → J'
  45. Angle(J, P, J') → θ
  46. Rotate(C, α, P) → C'_1
  47. Angle(C, P, C'_1) → ι
  48. Rotate(K, α, P) → K'
  49. Angle(K, P, K') → κ
  50. Polygon(J', C'_1, K') → poly4, k', j', c'_1
  51. Rotate(K, -α, O) → K'_1
  52. Angle(K'_1, O, K) → λ
  53. Rotate(L, -α, O) → L'
  54. Angle(L', O, L) → μ
  55. Rotate(D, -α, O) → D'_1
  56. Angle(D'_1, O, D) → ν
  57. Polygon(K'_1, D'_1, L') → poly5, l', k'_1, d'_1
  58. Rotate(A, -α, M) → A'_1
  59. Angle(A'_1, M, A) → ξ
  60. Rotate(I, -α, M) → I'
  61. Angle(I', M, I) → ο
  62. Rotate(J, -α, M) → J'_1
  63. Angle(J'_1, M, J) → ρ
  64. Polygon(J'_1, A'_1, I') → poly6, i', j'_1, a'_1
  65. Rotate(B, α, N) → B'_1
  66. Angle(B, N, B'_1) → σ
  67. Rotate(L, α, N) → L'_1
  68. Angle(L, N, L'_1) → τ
  69. Rotate(I, α, N) → I'_1
  70. Angle(I, N, I'_1) → υ
  71. Polygon(B'_1, L'_1, I'_1) → poly7, i'_1, b'_1, l'_1
  72. Segment(A', C') → n_2
  73. Polygon(C, E, D) → poly8, d_1, c_1, e_1
  74. Midpoint(A, C) → Q
  75. Midpoint(D, C) → R
  76. Midpoint(A, B) → S
  77. Midpoint(B, D) → T
  78. Segment(Q, T) → t
  79. Segment(S, R) → a_1
  80. Intersect(t, a_1) → U
  81. Point(e) → V
  82. Mirror(V, U) → V'
  83. Polygon(C, Q, V, B, T, V') → poly9, c_2, q_1, v, b_1, t_1, v'
  84. Rotate(A, α, Q) → A'_2
  85. Angle(A, Q, A'_2) → ϕ
  86. Rotate(V, α, Q) → V'_1
  87. Angle(V, Q, V'_1) → χ
  88. Polygon(Q, V'_1, A'_2) → poly10, a'_2, q_2, v'_1
  89. Rotate(V', α, T) → V''
  90. Angle(V', T, V'') → ψ
  91. Rotate(D, α, T) → D'_2
  92. Angle(D, T, D'_2) → ω
  93. Polygon(V'', D'_2, T) → poly11, t_2, v'', d'_2
  94. Segment(C, D) → f_1
  95. Segment(C, V') → g_1
  96. Segment(V, B) → h_1
  97. Segment(Q, C) → l_1
  98. Midpoint(A, C) → W
  99. Midpoint(B, D) → Z
  100. Segment(V, B) → m_1
  101. Point(m_1) → A_1
  102. Polygon(W, C, D, Z, A_1, V) → poly12, w, c_3, d_2, z, u_2, v_1
  103. Rotate(A_1, -α, Z) → B_1
  104. Angle(B_1, Z, A_1) → α_1
  105. Rotate(B, -α, Z) → B'_2
  106. Angle(B'_2, Z, B) → β_1
  107. Polygon(B_1, Z, B'_2) → poly13, b'_2, b_2, z_1
  108. Segment(E, C) → n_1
  109. Segment(C, D) → r_1
  110. Segment(E, D) → s_1
  111. Midpoint(s_1) → C_1
  112. Rotate(E, α, C_1) → E'_2
  113. Angle(E, C_1, E'_2) → γ_1
  114. Rotate(C, α, C_1) → C'_2
  115. Angle(C, C_1, C'_2) → δ_1
  116. Rotate(D, α, C_1) → D'_3
  117. Angle(D, C_1, D'_3) → ε_1
  118. Polygon(E'_2, C'_2, D'_3) → poly14, d'_3, e'_2, c'_2
  119. Midpoint(A, C) → D_1
  120. Midpoint(B, D) → E_1
  121. Mirror(V, D_1) → V'_2
  122. Mirror(A_1, E_1) → F_1
  123. Polygon(V, V'_2, F_1, A_1) → poly15, v_2, v'_2, f_2, a_2
  124. Midpoint(A_1, F_1) → G_1
  125. Rotate(A_1, α, G_1) → H_1
  126. Angle(A_1, G_1, H_1) → ζ_1
  127. Rotate(V, α, G_1) → V'_3
  128. Angle(V, G_1, V'_3) → η_1
  129. Rotate(V'_2, α, G_1) → I_1
  130. Angle(V'_2, G_1, I_1) → θ_1
  131. Rotate(F_1, α, G_1) → J_1
  132. Angle(F_1, G_1, J_1) → ι_1
  133. Polygon(V'_3, I_1, J_1, H_1) → poly16, v'_3, i_2, j_2, h_2
  134. Polygon(E'_1, A', C') → poly17, c'_3, e'_3, a'_3
  135. Polygon(A, C, D, B) → poly18, a_3, c_4, d_3, b_3
  136. Polygon(C, E, D) → poly19, d_4, c_5, e_2
  137. Polygon(E', B', D') → poly20, d'_4, e'_4, b'_3
  138. Polygon(A'_1, J'_1, I') → poly21, i'_2, a'_4, j'_2
  139. Polygon(B'_1, I'_1, L'_1) → poly22, l'_2, b'_4, i'_3
  140. Polygon(J', K', C'_1) → poly23, c'_4, j'_3, k'_2
  141. Polygon(K'_1, D'_1, L') → poly24, l'_3, k'_3, d'_5
  142. Polygon(A, C, D, B) → poly25, a_4, c_6, d_5, b_4
  143. Polygon(I, J, K, L) → poly26, i_3, j_3, k_2, l_2
  144. Polygon(V'_1, A'_2, Q) → poly27, q_3, v'_4, a'_5
  145. Polygon(D'_2, T, V'') → poly28, v''_1, d'_6, t_3
  146. Polygon(V, V'_1, V', V'') → poly29, v_3, v'_5, v'_6, v''_2
  147. Polygon(A, C, D, B) → poly30, a_5, c_7, d_6, b_5
  148. Point(b_5) → K_1
  149. Polygon(V'_1, A'_2, Q) → poly31, q_4, v'_7, a'_6
  150. Polygon(B_1, Z, B'_2) → poly32, b'_5, b_6, z_2
  151. Polygon(V, V'_1, B_1, A_1) → poly33, v_4, v'_8, b_7, a_6
  152. Polygon(A, C, D, B) → poly34, a_7, c_8, d_7, b_8
  153. Polygon(E, C, D) → poly35, d_8, e_3, c_9
  154. Polygon(D'_3, E'_2, C'_2) → poly36, c'_5, d'_7, e'_5
  155. Polygon(C'_2, E, C, D) → poly37, c'_6, e_4, c_{10}, d_9
  156. Polygon(V, V'_2, F_1, A_1) → poly38, v_5, v'_9, f_3, a_8
  157. Polygon(J_1, H_1, V'_3, I_1) → poly39, j_4, h_3, v'_{10}, i_4
  158. Polygon(V, V'_2, V'_3, I_1) → poly40, v_6, v'_{11}, v'_{12}, i_5
  159. Midpoint(A, E) → L_1
  160. Midpoint(E, B) → M_1
  161. Mirror(C, L_1) → C'_3
  162. Polygon(A, C, D, B) → poly41, a_9, c_{11}, d_{10}, b_9
  163. Polygon(L_1, C, D, M_1) → poly42, l_3, c_{12}, d_{11}, m_2
  164. Mirror(A, L_1) → A'_3
  165. Mirror(A'_3, L_1) → O_1
  166. Intersect(l_3, c_{12}) → P_1
  167. Rotate(O_1, -α, L_1) → Q_1
  168. Angle(Q_1, L_1, O_1) → κ_1
  169. Rotate(P_1, -α, L_1) → R_1
  170. Angle(R_1, L_1, P_1) → λ_1
  171. Polygon(Q_1, R_1, L_1) → poly43, l_4, q_5, r_2
  172. Rotate(D, α, M_1) → D'_4
  173. Angle(D, M_1, D'_4) → μ_1
  174. Rotate(B, α, M_1) → B'_3
  175. Angle(B, M_1, B'_3) → ν_1
  176. Polygon(M_1, B'_3, D'_4) → poly44, d'_8, m_3, b'_6
  177. Polygon(R_1, C, D) → poly45, d_{12}, r_3, c_{13}
  178. Circle(C, D) → p_2
  179. Line(A, B) → g_2
  180. Intersect(p_2, g_2) → N_1, S_1
  181. Polygon(A, C, D, B) → poly46, a_{10}, c_{14}, d_{13}, b_{10}
  182. Polygon(C, S_1, B, D) → poly47, c_{15}, s_2, b_{11}, d_{14}
  183. Segment(A, B) → g_3
  184. Midpoint(g_3) → T_1
  185. Rotate(A, -α, T_1) → A'_4
  186. Angle(A'_4, T_1, A) → ξ_1
  187. Segment(C, D) → k_3
  188. Midpoint(c_{14}) → U_1
  189. Rotate(C, -α, U_1) → C'_4
  190. Angle(C'_4, U_1, C) → ο_1
  191. Midpoint(S_1, B) → V_1
  192. Mirror(A, V_1) → A'_5
  193. Midpoint(S_1, A'_5) → W_1
  194. Rotate(S_1, -α, W_1) → Z_1
  195. Angle(Z_1, W_1, S_1) → ρ_1
  196. Polygon(A'_4, C'_4, Z_1) → poly48, z_3, a'_7, c'_7
  197. Polygon(C, S_1, Z_1, D) → poly49, c_{16}, s_3, z_4, d_{15}

AI Drawing Prompt Reference

Draw a quadrilateral by constructing lines, points, and arcs to explore its area. Start by drawing line segment AB, then construct a perpendicular line to AB, find the foot of the perpendicular C, draw line segment BC, construct its perpendicular line, and find the foot of the perpendicular D. Connect AD and BC, find the midpoints F and G of AD and BC, construct arcs with diameters E and D, E and C, then rotate points E, B, D to get E', B', D'. Construct quadrilateral E'B'D'. Next, rotate points A, E, C to get A', E'_1, C', and construct quadrilateral A'C'E'_1. Finally, find the midpoints I, J, L, K of line segments AB, EC, and construct quadrilateral JKIL, then rotate points J, C, K to get J', C'_1, K'.
The prompt above was compiled from the original drawing commands and is for reference only.