平行线与截线的性质探索

GeoGebra 命令及参数

1. Point(xAxis) → PEEPST
2. Polygon({PP1, PP2, PP3, PP4}) → peep
3. Point(Sequence[(k, -3.7), k, -3.5, -0.5, 0.2]) → T11
4. Point(Sequence[(k, -3.7), k, 0.5, 3.5, 0.2]) → T21
5. Point(Sequence[(k, 3.7), k, -3, -0.4, 0.2]) → T10
6. Line(T10, T11) → t1
7. Point(Sequence[(k, 3.7), k, 0.4, 3, 0.2]) → T20
8. Line(T20, T21) → t2
9. Intersect(ra, t1) → A
10. Intersect(rb, t1) → B
11. Intersect(rc, t1) → C
12. Intersect(rd, t1) → D
13. Intersect(ra, t2) → A'
14. Intersect(rb, t2) → B'
15. Intersect(rc, t2) → C'
16. Intersect(rd, t2) → D'
17. Segment(A, B) → segmAB
18. Segment(A', B') → segmAB'
19. Segment(C', D') → segmGreyCD'
20. Segment(A', B') → segmGreyAB'
21. Segment(C, D) → segmCD
22. Segment(C', D') → segmCD'
23. Line(A, t2) → parAt'
24. Line(C, t2) → parCt'
25. Intersect(parAt', rb) → E
26. Segment(A - (0.5 * UnitVector[parAt']), E + (0.5 * UnitVector[parAt'])) → segmLongAE
27. Intersect(parCt', rd) → F
28. Segment(C - (0.5 * UnitVector[parAt']), F + (0.5 * UnitVector[parAt'])) → segmLongCF
29. Polygon({A, B, E}) → trABE
30. Polygon({C, D, F}) → trCDF
31. Angle(B, A, E) → angBAE
32. Angle(E, B, A) → angABE
33. Angle(D, C, F) → angDCF
34. Angle(F, D, C) → angCDF
35. Segment(A, E) → segmAE
36. Segment(C, F) → segmCF
37. Polygon({A, A', B', E}) → quadAE
38. Polygon({C, C', D', F}) → quadCF