等腰梯形的性质 by tmoorehead

GeoGebra 命令及参数

1. Point(xAxis) → A
2. Point(xAxis) → B
3. Line(C, xAxis) → a
4. Angle(B, A, C) → α
5. Rotate(A, (-α), B) → A'
6. Angle(A', B, A) → β
7. Line(A', B) → b
8. Intersect(a, b) → D
9. Polygon(C, A, B, D) → poly1, c, a_1, b_1, d
10. Angle(poly1) → γ, δ, ε, ζ
11. Segment(A, D) → AD
12. Segment(C, B) → CB
13. Intersect(AD, CB) → E
14. Segment(E, D) → ED
15. Segment(E, B) → EB
16. Segment(E, A) → EA
17. Segment(E, C) → EC
18. Segment(A, C) → AC
19. Segment(C, D) → CD
20. Segment(D, B) → DB
21. Segment(A, B) → AB
22. Segment(A, D) → i
23. Segment(C, B) → j
24. Angle(j, i) → η
25. Segment(A, D) → l
26. Segment(B, C) → m
27. Angle(B, A, D) → θ
28. Angle(D, A, C) → ι
29. Angle(A, C, B) → κ
30. Angle(B, C, D) → λ
31. Angle(C, D, A) → μ
32. Angle(A, D, B) → ν
33. Angle(D, B, C) → ξ
34. Angle(C, B, A) → ο
35. Line(C, D) → p
36. Line(D, B) → q
37. Line(B, A) → r
38. Line(A, C) → s
39. Polygon(F, G, H, I) → poly2, f_1, g_1, h_1, i_1