Quiz: Constructing a Line with a Given Slope Using Δy/Δx

Quiz: Constructing a Line with a Given Slope Using Δy/Δx
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2021-03-25 02:57
This example, presented as a quiz, demonstrates how to construct a line with a specified slope on the coordinate plane starting from a chosen point, using the idea that slope is the ratio of changes Δy/Δx. It focuses on slope as a difference-and-ratio quantity, how to determine the direction of a line, and how the intercept-related parameters can be represented with simplified fractions. The construction uses GeoGebra commands such as Line and Segment to build the geometric entities, Slope and Angle (plus Distance) to measure and confirm slope and geometric relations, OrthogonalLine together with Intersect to obtain key perpendicular/meeting points, Vector and Midpoint to work with direction and central points, Dilate for scaling, and Mirror for reflections when needed for comparative structure. FractionText and fraction-related text objects display the computed numerator/denominator forms, while GCD and If support simplification of the slope ratio into reduced fractional values. Suitable for middle and high school learners to practice the geometric meaning of slope and its connection to coordinate-geometry reasoning.

GeoGebra Commands & Parameters

  1. GCD(deltaY, deltaX) → GCDm
  2. GCD(numerYint, deltaX) → GCDy
  3. If(sgn(deltaY / deltaX) ≥ 0, "", "-") → textSignN
  4. If(sgn(numerYint / deltaX) > 0, "+", "-") → textSign
  5. If(deltaXR ≟ 1, textSignN + deltaYR, textSignN + "\, \frac{" + deltaYR + "}{" + deltaXR + "}") → textslopeN
  6. If(denomYintR ≟ 1, textSign + numerYintR, textSign + "\frac{" + numerYintR + "}{" + denomYintR + "}") → textYint
  7. If(denomYintR ≟ 1, If[numerYintR ≟ 1, textSign, textSign + numerYintR], textSign + "\frac{" + numerYintR + "}{" + denomYintR + "}") → textMID
  8. OrthogonalLine(B, xAxis) → a_2
  9. OrthogonalLine(A, yAxis) → c
  10. Intersect(a_2, c) → C
  11. Line(A, B) → d
  12. Polygon(A, B, C) → poly1, c_1, a_1, b_1
  13. Distance(B, C) → distanceBC
  14. Distance(A, C) → distanceAC
  15. Intersect(a_2, c) → D
  16. Segment(A, D) → e
  17. Segment(C, B) → f
  18. GCD(deltaY_1, deltaX_1) → GCDm_1
  19. If(sgn(deltaY_1 / deltaX_1) ≥ 0, "", "-") → textSignN_1
  20. If(deltaXR_1 ≟ 1, textSignN_1 + deltaYR_1, textSignN_1 + "\, \frac{" + deltaYR_1 + "}{" + deltaXR_1 + "}") → textslopeN_1
  21. Line(A_1, B_1) → d_1
  22. Angle(B, D, A) → α
  23. Segment(A, B) → g
  24. GCD(deltaY_2, deltaX_2) → GCDm_2
  25. If(sgn(deltaY_2 / deltaX_2) ≥ 0, "", "-") → textSignN_2
  26. If(deltaXR_2 ≟ 1, textSignN_2 + deltaYR_2, textSignN_2 + "\, \frac{" + deltaYR_2 + "}{" + deltaXR_2 + "}") → textslopeN_2
  27. Line(A_2, B_2) → d_2
  28. Segment(A_2, B_2) → g_1
  29. GCD(deltaY_3, deltaX_3) → GCDm_3
  30. If(sgn(deltaY_3 / deltaX_3) ≥ 0, "", "-") → textSignN_3
  31. If(deltaXR_3 ≟ 1, textSignN_3 + deltaYR_3, textSignN_3 + "\, \frac{" + deltaYR_3 + "}{" + deltaXR_3 + "}") → textslopeN_3
  32. Line(A_3, B_3) → d_3
  33. Segment(A_3, B_3) → g_2
  34. Slope(g) → h
  35. Dilate(A, If[0 < i ≤ 1, 1 - i, 0], D) → A'
  36. Vector(A, A') → u
  37. Dilate(D, If[1 < i ≤ 2, 2 - i, 0], B) → D'
  38. Vector(D, D') → v
  39. Line(A, B) → j
  40. Midpoint(A, C) → E
  41. Mirror(B, k) → B'
  42. Distance(A, B') → distanceAB'
  43. Distance(B', B) → distanceB'B
  44. Polygon(A, B', B) → t1, b_5, a_6, b'
  45. Dilate(A, If[0 < i ≤ 1, 1 - i, 0], B') → A'_1
  46. Vector(A, A'_1) → w
  47. Dilate(B', If[1 < i ≤ 2, 2 - i, 0], B) → B''
  48. Vector(B', B'') → l
  49. Intersect(m, n) → F
  50. Dilate(A, If[0 < i ≤ 1, 1 - i, 0], F) → A'_2
  51. Vector(A, A'_2) → p
  52. Dilate(F, If[1 < i ≤ 2, 2 - i, 0], B) → F'
  53. Vector(F, F') → q
  54. Distance(A, F) → distanceAF
  55. Distance(F, B) → distanceFB
  56. Polygon(A, F, B) → t3, b_6, a_7, f_1
  57. FractionText(i_1) → text8
  58. Sequence(i, i, -10, 10, 1) → l1
  59. FractionText(m_1) → text1
  60. Dilate(pic1, 1 / 5, G) → pic1'
  61. Dilate(pic2, 1 / 5, I) → pic2'

AI Drawing Prompt Reference

Draw a line with a positive slope starting from the origin. First, draw the x-axis and y-axis. Then, select points A and B in the first quadrant, ensuring B is above and to the right of A. Draw a line d through points A and B and calculate its slope. Adjust the positions of points A and B to observe the change in slope and express it as a fraction. Finally, draw a line a_2 perpendicular to line d and find the intersection point C of lines d and a_2, forming a triangle.
The prompt above was compiled from the original drawing commands and is for reference only.