二十面体星形

GeoGebra 命令及参数

1. Point(Circle[Midpoint[A, B], (Distance[A, B] * sqrt(3) / 2), Segment[A, B]]) → C
2. Icosahedron(A, B, C) → a, D, faceABC, faceACF, faceAFG, faceADG, faceABD, faceBDH, faceBEH, faceBCE, faceCEI, faceCFI, E, faceEHK, faceEIK, faceIKL, faceFIL, faceHJK, faceJKL, faceGJL, faceFGL, faceDHJ, faceDGJ, F, edgeAC, edgeAB, edgeBC, edgeAF, edgeCF, edgeAG, edgeFG, edgeAD, edgeDG, edgeBD, G, edgeBH, edgeDH, edgeBE, edgeEH, edgeCE, edgeCI, edgeEI, edgeFI, edgeEK, edgeHK, H, edgeIK, edgeIL, edgeKL, edgeFL, edgeJK, edgeHJ, edgeJL, edgeGL, edgeGJ, edgeDJ, I, J, K, L
3. Line(G, J) → b
4. Line(B, H) → c
5. Intersect(c, b) → M
6. Pyramid(faceHJK, M) → d, faceJKM, faceHKM, faceHJM, edgeJM, edgeKM, edgeHM
7. Midpoint(D, I) → N
8. Mirror(d, N) → d'
9. Line(I, F) → e
10. Intersect(b, e) → O
11. Line(F, G) → f
12. Line(J, K) → g
13. Line(K, I) → h
14. Intersect(g, e) → P
15. Intersect(h, f) → Q
16. Intersect(f, g) → R
17. Pyramid(faceAFG, O) → i, faceAGO, faceAFO, faceFGO, edgeGO, edgeAO, edgeFO
18. Pyramid(faceCFI, Q) → j, faceCFQ, faceCIQ, faceFIQ, edgeFQ, edgeCQ, edgeIQ
19. Pyramid(faceEIK, P) → k, faceEIP, faceEKP, faceIKP, edgeIP, edgeEP, edgeKP
20. Pyramid(faceDGJ, R) → l, faceGJR, faceDJR, faceDGR, edgeGR, edgeJR, edgeDR
21. Mirror(i, N) → i'
22. Mirror(j, N) → j'
23. Mirror(k, N) → k'
24. Mirror(l, N) → l'
25. Line(I, E) → m
26. Line(J, H) → n
27. Line(J, D) → p
28. Line(F, A) → q
29. Line(G, A) → r
30. Intersect(q, p) → S
31. Pyramid(faceABD, S) → o, faceABS, faceADS, faceBDS, edgeBS, edgeAS, edgeDS
32. Intersect(m, n) → T
33. Pyramid(faceBEH, T) → s, faceBET, faceBHT, faceEHT, edgeET, edgeBT, edgeHT
34. Mirror(o, N) → o'
35. Mirror(s, N) → s'
36. Intersect(m, q) → U
37. Pyramid(faceFIL, U) → t, faceFIU, faceILU, faceFLU, edgeFU, edgeIU, edgeLU
38. Mirror(t, N) → t'
39. Intersect(n, r) → V
40. Pyramid(faceGJL, V) → u, faceGLV, faceJLV, faceGJV, edgeGV, edgeLV, edgeJV
41. Mirror(u, N) → u'
42. Line(H, B) → a_1
43. Intersect(a_1, r) → W
44. Pyramid(faceABC, W) → v, faceACW, faceABW, faceBCW, edgeCW, edgeAW, edgeBW
45. Mirror(v, N) → v'