三角形内角和定理 by sonom

GeoGebra 命令及参数

1. Segment(B, C) → a
2. Segment(C, A) → b
3. Segment(A, B) → c
4. Midpoint(c) → D
5. Circle(B, E) → d
6. Circle(C, F) → e
7. Intersect(d, c, 1) → G
8. Intersect(e, b, 1) → H
9. CircleSector(B, E, G) → f
10. CircleSector(C, H, F) → g
11. Rotate(B, (-γ), D) → B'
12. Rotate(E, (-γ), D) → E'
13. Rotate(G, (-γ), D) → G'
14. Sector(Rotate[Circle[B, E], (-γ), D], E', G') → A_1
15. Midpoint(b) → I
16. Rotate(C, γ, I) → C'
17. Rotate(H, γ, I) → H'
18. Rotate(F, γ, I) → F'
19. Sector(Rotate[Circle[C, H], γ, I], H', F') → A_2
20. Circle(A, 0.5) → h
21. Intersect(h, c) → J,
22. Intersect(h, b) → K,
23. CircleSector(A, J, K) → k
24. Line(A, a) → l