Explore the Area of a Triangle

Explore the Area of a Triangle
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2020-05-06 02:06
In collections The Area of a Triangle
This example explores the area of a triangle, helping students understand the triangle area formula and its applications. Key mathematical concepts include the triangle area formula, geometric transformations, and similar triangles. Using GeoGebra commands such as Circle, Point, Segment, Line, etc., students can dynamically observe and understand the changes in the triangle's area. Suitable for middle school and above students to learn geometric construction and area calculation.

GeoGebra Commands & Parameters

  1. Circle(A, Height) → c
  2. Circle(A, Base) → d
  3. Point(d) → B
  4. Segment(A, B) → e
  5. Line(A, B) → f
  6. OrthogonalLine(A, f) → g
  7. Intersect(c, g, 1) → C
  8. Tangent(C, c) → h, a
  9. Point(h) → D
  10. Polygon(A, B, D) → P, d_1, a_1, b_1
  11. OrthogonalLine(D, f) → i
  12. Intersect(f, i) → E
  13. Segment(E, D) → j
  14. Segment(E, B) → k
  15. Midpoint(D, B) → F
  16. Midpoint(D, A) → G
  17. Point(a_1) → H
  18. Circle(B, H) → p
  19. Intersect(p, d_1, 1) → I
  20. OrthogonalLine(H, a_1) → l
  21. OrthogonalLine(I, d_1) → m
  22. Intersect(l, m) → J
  23. If(x(D) ≟ x(B), G) → K
  24. If(x(D) ≟ x(B), J) → L
  25. Segment(L, H) → n
  26. Segment(L, I) → q
  27. Rotate(A, α, K) → A'
  28. Rotate(B, α, K) → B'
  29. Rotate(D, α, K) → D'
  30. Polygon(A', B', D') → P', d', a', b'
  31. If(x(D) ≟ x(A), F) → M
  32. Point(b_1) → N
  33. Circle(A, N) → r
  34. Intersect(r, d_1, 1) → O
  35. OrthogonalLine(N, b_1) → s
  36. OrthogonalLine(O, d_1) → t
  37. Intersect(s, t) → Q
  38. If(x(D) ≟ x(A), Q) → R
  39. Segment(N, R) → c_1
  40. Segment(R, O) → e_1
  41. Rotate(A, -α, M) → A'_1
  42. Rotate(B, -α, M) → B'_1
  43. Rotate(D, -α, M) → D'_1
  44. Polygon(A'_1, B'_1, D'_1) → P'_1, d'_1, a'_1, b'_1
  45. If(x(D) > x(B), G) → S
  46. Rotate(A, α, S) → A'_2
  47. Rotate(B, α, S) → B'_2
  48. Rotate(D, α, S) → D'_2
  49. Polygon(A'_2, B'_2, D'_2) → P'_2, d'_2, a'_2, b'_2
  50. If(x(D) < x(A), F) → T
  51. Rotate(A, -α, T) → A'_3
  52. Rotate(B, -α, T) → B'_3
  53. Rotate(D, -α, T) → D'_3
  54. Polygon(A'_3, B'_3, D'_3) → P'_3, d'_3, a'_3, b'_3
  55. If((x(D) > x(A)) ∧ (x(D) < x(B)), F) → U
  56. Rotate(A, -α, U) → A'_4
  57. Rotate(B, -α, U) → B'_4
  58. Rotate(D, -α, U) → D'_4
  59. Polygon(A'_4, B'_4, D'_4) → P'_4, d'_4, a'_4, b'_4
  60. Midpoint(D, E) → V
  61. Midpoint(A, B) → W

AI Drawing Prompt Reference

Draw a triangle and perform geometric transformations including rotations and reflections. Start by drawing a circle with center A and height as radius, then draw a circle with center A and base as radius to determine point B, connect A and B to form the base, draw a perpendicular line to AB to determine point C, draw a tangent to the circle through C to determine point D, connect AD and BD, find the midpoint F of AD and G of BD, draw a circle with center D, determine point H, draw a tangent to the circle through H to determine point I, draw a tangent to the circle through I to determine point J, rotate triangle ABC to get triangle A'B'D', then rotate triangle ABC to get triangle A''B''D''.
The prompt above was compiled from the original drawing commands and is for reference only.