五边形、十边形与二十面体关系演示

GeoGebra 命令及参数

1. Point(Circle[Midpoint[(0, 0), (2, 0)], (Distance[(0, 0), (2, 0)] * sqrt(3) / 2), Segment[(0, 0), (2, 0)]]) → A_1
2. Icosahedron((0, 0), (2, 0), A_1) → a, B_1, face1, face3, face5, face4, face2, face7, face8, face6, faceACG, faceADG, C_1, faceCFI, faceCGI, faceGIJ, faceDGJ, faceFHI, faceHIJ, faceEHJ, faceDEJ, faceBFH, faceBEH, D_1, edge2, edge1, edge6, edge4, edgeAD, edge5, edgeDE, edge3, edgeBE, edge7, E_1, edge9, edgeBF, edge8, edgeCF, edgeAC, edgeAG, edgeCG, edgeDG, edgeCI, edgeFI, P, edgeGI, edgeGJ, edgeIJ, edgeDJ, edgeHI, edgeFH, edgeHJ, edgeEJ, edgeEH, edgeBH, G, A, C, J
3. Polygon(E_1, B_1, P, C, J) → poly1, e, b, f, i, j
4. Line(A, A_1) → g
5. Circle(g, P) → c
6. Plane(B_1, P, J) → d
7. Intersect(g, d) → B
8. Segment(B, P) → h
9. Point(xAxis) → R
10. Line(R, g) → k
11. Intersect(k, c) → Q,
12. Segment(Q, B) → l
13. Segment(Q, P) → m
14. Segment(Q, B_1) → n
15. Line(A, l) → p
16. Segment(R, Q) → q
17. Segment(B, A) → r
18. Segment(B, C) → s
19. Angle(A, B, C) → α
20. Angle(P, Q, R) → β