Volume via Triangular Cross Sections

Volume via Triangular Cross Sections
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2015-11-02 06:02
This example is designed to help visualize objects constructed from triangular cross sections. Users can set the type of triangle, two functions, limits, axis of rotation, and number of sections. Adjusting these parameters allows for a visual understanding of volume changes under different conditions. Key mathematical concepts include integral calculus and solid geometry. The construction utilizes GeoGebra commands and objects such as Intersect, Textfield, Min, Max, IntegralBetween, Segment, Plane, SelectedIndex, and Polygon. It is suitable for high school and above students learning volume calculation methods, particularly in calculus and solid geometry education.

GeoGebra Commands & Parameters

  1. Intersect(g, l_c, (1, 1)) → P_{gc1}
  2. Intersect(f, l_c, (1, 1)) → P_{fc1}
  3. Textfield(a) → inputBox_a
  4. Textfield(b) → inputBox_b
  5. Min(abs(rad_f), abs(rad_g)) → rad_i
  6. Max(abs(rad_f), abs(rad_g)) → rad_o
  7. Intersect(f, l_b, (5, 5)) → P_{fb}
  8. Intersect(g, l_b, (5, 0.2)) → P_{gb}
  9. Intersect(f, l_a, (1, 1)) → P_{fa}
  10. Intersect(g, l_a, (1, 1)) → P_{ga}
  11. IntegralBetween(f, g, Min[x(P_{fa}), x(P_{ga})], Max[x(P_{fb}), x(P_{gb})]) → R
  12. Segment((0, y_{rotation}), (0, If[abs(rad_f) ≥ abs(rad_g), y(P_{fc1}), y(P_{gc1})])) → r_o
  13. Segment((0, y_{rotation}), (0, If[abs(rad_f) < abs(rad_g), y(P_{fc1}), y(P_{gc1})])) → r_i
  14. Plane((x_i, y_{rotation}, rad_o), x = x_i) → pln3d
  15. Textfield(n) → InputBox1
  16. SelectedIndex(opt) → optIndex
  17. Polygon(P_{fc1}, P_{gc1}, opt_{v1}(SelectedIndex[opt])) → crosssec_1, seg_{11}, seg_{12}, seg_{13}
  18. Polygon(P_{fc2}, P_{gc2}, opt_{v2}(SelectedIndex[opt])) → crosssec_2, seg_{21}, seg_{22}, seg_{23}
  19. Polygon(P_{fc1}, P_{gc1}, opt_{v3}(SelectedIndex[opt])) → crosssec_3, seg_{31}, seg_{32}, seg_{33}
  20. SelectedIndex(lstTraceOpt) → lstTOIndex
  21. Textfield(tf) → InputBox_f
  22. Textfield(tg) → InputBox_g