Sine Rule – Find a Side Demonstration

Sine Rule – Find a Side Demonstration
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2012-12-05 08:04
① This example shows how to apply the Sine Rule to determine an unknown side length in a triangle when two angles and one side or two sides and one angle are known. ② Core mathematical concepts include the Sine Rule, triangle angle sum, side‑angle correspondence, and trigonometric function definitions. ③ Construction highlights: Points are created with Point; Rotate builds equal angles; Line and Intersect locate intersections; Segment draws sides; Angle marks angles; Midpoint and Vector support auxiliary relationships; text objects (text2, text5, etc.) display dynamic calculations. ④ Suitable for high‑school trigonometry lessons, student inquiry activities, exam review, and as a GeoGebra geometric construction tutorial.

GeoGebra Commands & Parameters

  1. Point(Circle[Q, b]) → P
  2. Rotate(Q, (angleA + angleB)°, P) → Q'_1
  3. Line(Q'_1, P) → c_1
  4. Rotate(P, angleA°, Q) → P'_1
  5. Line(Q, P'_1) → b_1
  6. Intersect(c_1, b_1) → R
  7. Segment(P, Q) → b_2
  8. Segment(Q, R) → c
  9. Segment(R, P) → a
  10. Angle(P, R, Q) → β
  11. Angle(Q, P, R) → γ
  12. Angle(R, Q, P) → α
  13. Midpoint(a) → A'
  14. Midpoint(c) → C'
  15. Midpoint(b_2) → B'
  16. Segment(Q, P) → a_1
  17. Angle(P, Q, P'_1) → α_2
  18. Angle(Q, P, Q'_1) → β_2
  19. Vector(Q, A') → u
  20. Vector(R, B') → v
  21. Vector(P, C') → w

AI Drawing Prompt Reference

Draw a triangle with vertices P, Q, R constructed from two known angles and one side or two sides and one angle by rotating rays to create equal‑angle lines that intersect at the third vertex. Mark the three interior angles α, β, γ, show the three sides with their lengths, indicate the midpoint of each side, and draw vectors from each vertex to the midpoint of the opposite side. Also display the auxiliary rotated lines used in the construction.
The prompt above was compiled from the original drawing commands and is for reference only.