Feuerbach Circle

Feuerbach Circle
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2020-10-16 15:04
This example demonstrates the Feuerbach circle, also known as the nine-point circle, which involves the properties of triangles, particularly the midpoints, feet of altitudes, and circumcenter. Using GeoGebra commands such as Segment, OrthogonalLine, and Intersect, the construction of the Feuerbach circle is shown. Suitable for high school mathematics education and learning, especially for geometric construction and triangle-related concepts.

GeoGebra Commands & Parameters

  1. Segment(B, C) → a
  2. Segment(C, A) → b
  3. Segment(A, B) → c
  4. OrthogonalLine(C, c) → f
  5. OrthogonalLine(A, a) → g
  6. OrthogonalLine(B, b) → h
  7. Intersect(h, b) → E
  8. Intersect(f, c) → F
  9. Intersect(g, a) → D
  10. Segment(C, F) → i
  11. Segment(A, D) → j
  12. Segment(E, B) → k
  13. Angle(B, F, C) → α
  14. Angle(C, D, A) → β
  15. Angle(A, E, B) → γ
  16. Intersect(i, j) → V
  17. Midpoint(C, V) → Q
  18. Midpoint(A, V) → R
  19. Midpoint(B, V) → P
  20. Midpoint(A, B) → C'
  21. Midpoint(B, C) → A'
  22. Midpoint(A, C) → B'
  23. Segment(Q, P) → l
  24. Segment(Q, B') → m
  25. Segment(P, C') → n
  26. Segment(C', B') → p
  27. Angle(P, C', B') → δ
  28. Angle(C', B', Q) → ε
  29. Angle(B', Q, P) → ζ
  30. Angle(Q, P, C') → η
  31. Segment(Q, C') → q
  32. Segment(B', P) → r
  33. Intersect(q, r) → S
  34. Circle(S, Q) → d
  35. LineBisector(A, B) → s
  36. LineBisector(A, C) → t
  37. LineBisector(B, C) → e
  38. Intersect(s, t) → G
  39. Segment(G, V) → f_1
  40. Segment(A', Q) → g_1
  41. Segment(Q, R) → h_1
  42. Segment(R, C') → i_1
  43. Segment(C', A') → j_1
  44. Angle(Q, A', C') → θ
  45. Angle(C', R, Q) → ι
  46. Segment(R, A') → k_1

AI Drawing Prompt Reference

Please draw the nine-point circle. The nine-point circle is a special circle of a triangle that passes through the midpoints of the sides, the feet of the altitudes, and the nine-point circle's center. First, draw a triangle. Then, construct the altitudes from the vertices to the opposite sides to find the feet. Next, find the midpoints of the triangle's sides. Finally, draw the nine-point circle with the nine-point circle's center as the center.
The prompt above was compiled from the original drawing commands and is for reference only.