Clock-Face Symmetry via Geometric Construction

Clock-Face Symmetry via Geometric Construction
Loading the math board and drawing, please wait…
2021-01-01 09:06
This example demonstrates “around-the-clock” (clock-face) symmetries by using geometric construction to map points and triangles into repeated positions through reflection. It visualizes how mirrored copies generate patterned polygons and consistent similarity structures. Key concepts include geometric transformation—especially Mirror (reflection)—together with core construction tools like Intersect, Point, Line, and Polygon to build the initial configuration and its reflected images. The construction uses objects such as the base triangle/polygon shapes (poly1, poly2) and their mirrored counterparts (poly1', poly2'), created by mirroring points (e.g., D, E, F and D', E', F'), along with intersection-based points and derived helper variables (such as d, e, g, h and their primed versions). The result is a clear, step-by-step illustration of how symmetry produces repeating geometric structure. Suitable for middle/high school geometry classes and interactive teaching on symmetry, similar triangles, and geometric construction techniques.

GeoGebra Commands & Parameters

  1. Intersect(xAxis, yAxis) → A
  2. Point(xAxis) → C
  3. Line(A, C) → a
  4. Line(A, B) → b
  5. Polygon(D, E, F) → poly1, f, d, e
  6. Mirror(D, a) → D'
  7. Mirror(E, a) → E'
  8. Mirror(F, a) → F'
  9. Polygon(D', E', F') → poly1', f', d', e'
  10. Mirror(D, b) → D'_1
  11. Mirror(E, b) → E'_1
  12. Mirror(F, b) → F'_1
  13. Polygon(D'_1, E'_1, F'_1) → poly1'_1, f'_1, d'_1, e'_1
  14. Mirror(D'_1, a) → G
  15. Mirror(E'_1, a) → H
  16. Mirror(F'_1, a) → I
  17. Polygon(G, H, I) → poly2, i, g, h
  18. Mirror(G, b) → G'
  19. Mirror(H, b) → H'
  20. Mirror(I, b) → I'
  21. Polygon(G', H', I') → poly2', i', g', h'
  22. Mirror(G', a) → G''
  23. Mirror(H', a) → H''
  24. Mirror(I', a) → I''
  25. Polygon(G'', H'', I'') → poly2'', i'', g'', h''
  26. Mirror(G'', b) → G'''
  27. Mirror(H'', b) → H'''
  28. Mirror(I'', b) → I'''
  29. Polygon(G''', H''', I''') → poly2''', i''', g''', h'''
  30. Mirror(G''', a) → J
  31. Mirror(H''', a) → K
  32. Mirror(I''', a) → L
  33. Polygon(J, K, L) → poly3, l, j, k
  34. Mirror(J, b) → J'
  35. Mirror(K, b) → K'
  36. Mirror(L, b) → L'
  37. Polygon(J', K', L') → poly3', l', j', k'
  38. Mirror(J', a) → J''
  39. Mirror(K', a) → K''
  40. Mirror(L', a) → L''
  41. Polygon(J'', K'', L'') → poly3'', l'', j'', k''
  42. Mirror(J'', b) → J'''
  43. Mirror(K'', b) → K'''
  44. Mirror(L'', b) → L'''
  45. Polygon(J''', K''', L''') → poly3''', l''', j''', k'''
  46. Mirror(J''', a) → M
  47. Mirror(K''', a) → N
  48. Mirror(L''', a) → O
  49. Polygon(M, N, O) → poly4, o, m, n_1
  50. Mirror(M, b) → M'
  51. Mirror(N, b) → N'
  52. Mirror(O, b) → O'
  53. Polygon(M', N', O') → poly4', o', m', n'
  54. Mirror(M', a) → M''
  55. Mirror(N', a) → N''
  56. Mirror(O', a) → O''
  57. Polygon(M'', N'', O'') → poly4'', o'', m'', n''
  58. Mirror(M'', b) → M'''
  59. Mirror(N'', b) → N'''
  60. Mirror(O'', b) → O'''
  61. Polygon(M''', N''', O''') → poly4''', o''', m''', n'''
  62. Mirror(M''', a) → P
  63. Mirror(N''', a) → Q
  64. Mirror(O''', a) → R
  65. Polygon(P, Q, R) → poly5, r, p, q
  66. Mirror(P, b) → P'
  67. Mirror(Q, b) → Q'
  68. Mirror(R, b) → R'
  69. Polygon(P', Q', R') → poly5', r', p', q'
  70. Mirror(P', a) → P''
  71. Mirror(Q', a) → Q''
  72. Mirror(R', a) → R''
  73. Polygon(P'', Q'', R'') → poly5'', r'', p'', q''
  74. Mirror(P'', b) → P'''
  75. Mirror(Q'', b) → Q'''
  76. Mirror(R'', b) → R'''
  77. Polygon(P''', Q''', R''') → poly5''', r''', p''', q'''
  78. Mirror(P''', a) → S
  79. Mirror(Q''', a) → T
  80. Mirror(R''', a) → U
  81. Polygon(S, T, U) → poly6, u, s, t
  82. Mirror(S, b) → S'
  83. Mirror(T, b) → T'
  84. Mirror(U, b) → U'
  85. Polygon(S', T', U') → poly6', u', s', t'
  86. Mirror(S', a) → S''
  87. Mirror(T', a) → T''
  88. Mirror(U', a) → U''
  89. Polygon(S'', T'', U'') → poly6'', u'', s'', t''
  90. Mirror(S'', b) → S'''
  91. Mirror(T'', b) → T'''
  92. Mirror(U'', b) → U'''
  93. Polygon(S''', T''', U''') → poly6''', u''', s''', t'''
  94. Mirror(S''', a) → V
  95. Mirror(T''', a) → W
  96. Mirror(U''', a) → Z
  97. Polygon(V, W, Z) → poly7, z, v, w
  98. Mirror(V, b) → V'
  99. Mirror(W, b) → W'
  100. Mirror(Z, b) → Z'
  101. Polygon(V', W', Z') → poly7', z', v', w'
  102. Mirror(V', a) → V''
  103. Mirror(W', a) → W''
  104. Mirror(Z', a) → Z''
  105. Polygon(V'', W'', Z'') → poly7'', z'', v'', w''
  106. Mirror(V'', b) → V'''
  107. Mirror(W'', b) → W'''
  108. Mirror(Z'', b) → Z'''
  109. Polygon(V''', W''', Z''') → poly7''', z''', v''', w'''
  110. Mirror(V''', a) → A_1
  111. Mirror(W''', a) → B_1
  112. Mirror(Z''', a) → C_1
  113. Polygon(A_1, B_1, C_1) → poly8, c_1, a_1, b_1
  114. Mirror(A_1, b) → D_1
  115. Mirror(B_1, b) → E_1
  116. Mirror(C_1, b) → F_1
  117. Polygon(D_1, E_1, F_1) → poly8', f_1, d_1, e_1
  118. Mirror(D_1, a) → G_1
  119. Mirror(E_1, a) → H_1
  120. Mirror(F_1, a) → I_1
  121. Polygon(G_1, H_1, I_1) → poly8'', i_1, g_1, h_1
  122. Mirror(G_1, b) → J_1
  123. Mirror(H_1, b) → K_1
  124. Mirror(I_1, b) → L_1
  125. Polygon(J_1, K_1, L_1) → poly8''', l_1, j_1, k_1
  126. Mirror(J_1, a) → M_1
  127. Mirror(K_1, a) → N_1
  128. Mirror(L_1, a) → O_1
  129. Polygon(M_1, N_1, O_1) → poly9, o_1, m_1, n_2
  130. Mirror(M_1, b) → P_1
  131. Mirror(N_1, b) → Q_1
  132. Mirror(O_1, b) → R_1
  133. Polygon(P_1, Q_1, R_1) → poly9', r_1, p_1, q_1
  134. Mirror(P_1, a) → S_1
  135. Mirror(Q_1, a) → T_1
  136. Mirror(R_1, a) → U_1
  137. Polygon(S_1, T_1, U_1) → poly9'', u_1, s_1, t_1
  138. Mirror(S_1, b) → V_1
  139. Mirror(T_1, b) → W_1
  140. Mirror(U_1, b) → Z_1
  141. Polygon(V_1, W_1, Z_1) → poly9''', z_1, v_1, w_1
  142. Mirror(V_1, a) → A_2
  143. Mirror(W_1, a) → B_2
  144. Mirror(Z_1, a) → C_2
  145. Polygon(A_2, B_2, C_2) → poly10, c_2, a_2, b_2
  146. Mirror(A_2, b) → D_2
  147. Mirror(B_2, b) → E_2
  148. Mirror(C_2, b) → F_2
  149. Polygon(D_2, E_2, F_2) → poly10', f_2, d_2, e_2
  150. Mirror(D_2, a) → G_2
  151. Mirror(E_2, a) → H_2
  152. Mirror(F_2, a) → I_2
  153. Polygon(G_2, H_2, I_2) → poly10'', i_2, g_2, h_2
  154. Mirror(G_2, b) → J_2
  155. Mirror(H_2, b) → K_2
  156. Mirror(I_2, b) → L_2
  157. Polygon(J_2, K_2, L_2) → poly10''', l_2, j_2, k_2
  158. Mirror(J_2, a) → M_2
  159. Mirror(K_2, a) → N_2
  160. Mirror(L_2, a) → O_2
  161. Polygon(M_2, N_2, O_2) → poly11, o_2, m_2, n_3
  162. Mirror(M_2, b) → P_2
  163. Mirror(N_2, b) → Q_2
  164. Mirror(O_2, b) → R_2
  165. Polygon(P_2, Q_2, R_2) → poly11', r_2, p_2, q_2
  166. Mirror(P_2, a) → S_2
  167. Mirror(Q_2, a) → T_2
  168. Mirror(R_2, a) → U_2
  169. Polygon(S_2, T_2, U_2) → poly11'', u_2, s_2, t_2
  170. Mirror(S_2, b) → V_2
  171. Mirror(T_2, b) → W_2
  172. Mirror(U_2, b) → Z_2
  173. Polygon(V_2, W_2, Z_2) → poly11''', z_2, v_2, w_2
  174. Mirror(V_2, a) → A_3
  175. Mirror(W_2, a) → B_3
  176. Mirror(Z_2, a) → C_3
  177. Polygon(A_3, B_3, C_3) → poly12, c_3, a_3, b_3
  178. Mirror(A_3, b) → D_3
  179. Mirror(B_3, b) → E_3
  180. Mirror(C_3, b) → F_3
  181. Polygon(D_3, E_3, F_3) → poly12', f_3, d_3, e_3
  182. Mirror(D_3, a) → G_3
  183. Mirror(E_3, a) → H_3
  184. Mirror(F_3, a) → I_3
  185. Polygon(G_3, H_3, I_3) → poly12'', i_3, g_3, h_3
  186. Mirror(G_3, b) → J_3
  187. Mirror(H_3, b) → K_3
  188. Mirror(I_3, b) → L_3
  189. Polygon(J_3, K_3, L_3) → poly12''', l_3, j_3, k_3
  190. Mirror(J_3, a) → M_3
  191. Mirror(K_3, a) → N_3
  192. Mirror(L_3, a) → O_3
  193. Polygon(M_3, N_3, O_3) → poly13, o_3, m_3, n_4
  194. Mirror(M_3, b) → P_3
  195. Mirror(N_3, b) → Q_3
  196. Mirror(O_3, b) → R_3
  197. Polygon(P_3, Q_3, R_3) → poly13', r_3, p_3, q_3
  198. Mirror(P_3, a) → S_3
  199. Mirror(Q_3, a) → T_3
  200. Mirror(R_3, a) → U_3
  201. Polygon(S_3, T_3, U_3) → poly13'', u_3, s_3, t_3
  202. Mirror(S_3, b) → V_3
  203. Mirror(T_3, b) → W_3
  204. Mirror(U_3, b) → Z_3
  205. Polygon(V_3, W_3, Z_3) → poly13''', z_3, v_3, w_3
  206. Mirror(V_3, a) → A_4
  207. Mirror(W_3, a) → B_4
  208. Mirror(Z_3, a) → C_4
  209. Polygon(A_4, B_4, C_4) → poly14, c_4, a_4, b_4
  210. Mirror(A_4, b) → D_4
  211. Mirror(B_4, b) → E_4
  212. Mirror(C_4, b) → F_4
  213. Polygon(D_4, E_4, F_4) → poly14', f_4, d_4, e_4
  214. Mirror(D_4, a) → G_4
  215. Mirror(E_4, a) → H_4
  216. Mirror(F_4, a) → I_4
  217. Polygon(G_4, H_4, I_4) → poly14'', i_4, g_4, h_4
  218. Mirror(G_4, b) → J_4
  219. Mirror(H_4, b) → K_4
  220. Mirror(I_4, b) → L_4
  221. Polygon(J_4, K_4, L_4) → poly14''', l_4, j_4, k_4
  222. Mirror(J_4, a) → M_4
  223. Mirror(K_4, a) → N_4
  224. Mirror(L_4, a) → O_4
  225. Polygon(M_4, N_4, O_4) → poly15, o_4, m_4, n_5
  226. Mirror(M_4, b) → P_4
  227. Mirror(N_4, b) → Q_4
  228. Mirror(O_4, b) → R_4
  229. Polygon(P_4, Q_4, R_4) → poly15', r_4, p_4, q_4
  230. Mirror(P_4, a) → S_4
  231. Mirror(Q_4, a) → T_4
  232. Mirror(R_4, a) → U_4
  233. Polygon(S_4, T_4, U_4) → poly15'', u_4, s_4, t_4
  234. Mirror(S_4, b) → V_4
  235. Mirror(T_4, b) → W_4
  236. Mirror(U_4, b) → Z_4
  237. Polygon(V_4, W_4, Z_4) → poly15''', z_4, v_4, w_4
  238. Mirror(V_4, a) → A_5
  239. Mirror(W_4, a) → B_5
  240. Mirror(Z_4, a) → C_5
  241. Polygon(A_5, B_5, C_5) → poly16, c_5, a_5, b_5

AI Drawing Prompt Reference

Draw a geometric construction starting with two intersecting lines from the origin and a point on the horizontal axis. Create an initial triangle, then repeatedly reflect it across these two lines in alternating order. After each reflection, connect the three reflected vertices to form a new triangle, and continue reflecting these new triangles to generate multiple symmetric copies arranged around the center like a clock face. The final image shows a pattern of triangles radiating outward with clear mirror symmetry, demonstrating repeated reflection transformations.
The prompt above was compiled from the original drawing commands and is for reference only.