内切圆与外切圆及纳格尔点

内切圆与外切圆及纳格尔点
几何画板及绘图内容加载中,请稍等……
2015-02-12 06:27
本示例展示了三角形的四个切圆(内切圆和三个外切圆)以及纳格尔点。纳格尔点是三角形内切圆与外切圆切点连线的交点。本示例涉及三角形的切圆和纳格尔点的概念,使用了Segment, AngularBisector, Intersect, OrthogonalLine, Circle, Line等GeoGebra命令。适合高中几何学习。

GeoGebra 命令及参数

  1. Segment(A, B) → a
  2. Segment(B, C) → b
  3. Segment(C, A) → c
  4. AngularBisector(A, B, C) → d
  5. AngularBisector(C, A, B) → e
  6. AngularBisector(B, C, A) → f
  7. Intersect(d, e) → I
  8. OrthogonalLine(I, c) → g
  9. Intersect(g, c) → D
  10. Circle(I, D) → h
  11. Intersect(h, a, 1) → E
  12. Intersect(h, b, 1) → F
  13. Line(A, B) → i
  14. Line(B, C) → j
  15. Line(C, A) → k
  16. OrthogonalLine(B, d) → l
  17. OrthogonalLine(A, e) → m
  18. Intersect(e, l) → G
  19. Intersect(f, l) → H
  20. Intersect(d, m) → J
  21. OrthogonalLine(G, j) → p
  22. OrthogonalLine(H, i) → n
  23. OrthogonalLine(J, k) → q
  24. Intersect(i, n) → K
  25. Circle(H, K) → r
  26. Intersect(k, q) → L
  27. Circle(J, L) → s
  28. Intersect(j, p) → M
  29. Circle(G, M) → t
  30. OrthogonalLine(C, f) → a_1
  31. Segment(K, C) → b_1
  32. Segment(B, L) → c_1
  33. Segment(A, M) → d_1
  34. Intersect(b_1, c_1) → N