勾股定理证明 by milanofff

勾股定理证明 by milanofff
几何画板及绘图内容加载中,请稍等……
2012-07-22 18:01
①本范例演示勾股定理的几何证明方法;②涉及核心数学概念包括直角三角形、面积、全等三角形、平行四边形;③作图要点:使用 GeoGebra 命令如 Midpoint(中点)、Polygon(多边形)、Segment(线段)、Intersect(交点)、Rotate(旋转)、Line(直线)、OrthogonalLine(垂线)、Distance(距离)、Circle(圆)、Vector(向量)、Translate(平移)等构建图形;④适合初中及以上学生学习和理解勾股定理的证明过程及几何性质。

GeoGebra 命令及参数

  1. Midpoint(B, A) → M
  2. Polygon(A, B, 4) → square, bsq, asq, csq, dsq, C_1, D
  3. Segment(A, C_1) → d_1
  4. Segment(B, D) → d_2
  5. Intersect(d_1, d_2) → O
  6. Rotate(A, rot°, M) → C
  7. Polygon(A, C, B) → brown, b, a, b_1
  8. Line(C, B) → m
  9. OrthogonalLine(Z, m) → n
  10. OrthogonalLine(Y, m) → p
  11. Intersect(m, n) → N
  12. Intersect(m, p) → P
  13. Distance(N, P) → r
  14. Circle(B, If[r1 > 0, 0, (-r1) / 40]) → cred
  15. Circle(B, If[r1 > 0, 0, (-r1) / 20]) → cblue
  16. Intersect(cred, m, 1) → BR
  17. Intersect(cred, m, 2) → BG
  18. Intersect(cblue, m, 2) → BB
  19. Vector(B, C) → u
  20. Vector(B, A) → v
  21. Translate(BR, u) → B_1R
  22. Translate(BR, v) → AR
  23. Polygon(AR, B_1R, BR) → red, br, ar, b_1r
  24. Translate(BG, u) → B_1G
  25. Translate(BG, v) → AG
  26. Translate(BB, u) → B_1B
  27. Translate(BB, v) → AB
  28. Rotate(A, If[r1 ≤ 0, 0*°, (3 * r1 / 4)°], O) → A1
  29. Rotate(C, If[r1 ≤ 0, 0*°, (3 * r1 / 4)°], O) → E
  30. Rotate(B, If[r1 ≤ 0, 0*°, (3 * r1 / 4)°], O) → B1
  31. Polygon(A1, E, B1) → red1, b1, a1, b1_1
  32. Rotate(A, If[r1 ≤ 0, 0*°, (r1 / 2)°], O) → A2
  33. Rotate(B, If[r1 ≤ 0, 0*°, (r1 / 2)°], O) → B2
  34. Rotate(A, If[r1 ≤ 0, 0*°, (r1 / 4)°], O) → A3
  35. Rotate(B, If[r1 ≤ 1, 0*°, (r1 / 4)°], O) → B3
  36. Angle(BR, B_1R, AR) → α
  37. Angle(B, C, A) → β
  38. Angle(B1, E, A1) → γ
  39. Polygon(A, B, D) → poly1, d, a_1, b_2