Co-interior Angles Theorem

Co-interior Angles Theorem
Loading the math board and drawing, please wait…
2020-04-27 14:39
This example illustrates the co-interior angles theorem, where the sum of co-interior angles formed by two lines intersected by a third line is 180 degrees. Key concepts include angles, straight lines, and geometric construction. It utilizes commands such as point, rotate, angle, line, circle, and intersect in GeoGebra. Suitable for middle school and above students studying geometry.

GeoGebra Commands & Parameters

  1. Point(a) → B
  2. Rotate(B, α, A) → B'
  3. Angle(B, A, B') → β
  4. Line(A, B') → b
  5. Circle(A, 1) → e
  6. Intersect(b, d) → C
  7. Circle(C, 1) → f
  8. Intersect(e, a) → D, E
  9. Intersect(e, b) → F, G
  10. Intersect(f, b) → H, I
  11. Intersect(f, d) → J, K
  12. CircleSector(C, K, I) → g
  13. CircleSector(C, I, J) → h
  14. CircleSector(C, J, H) → k
  15. CircleSector(C, H, K) → p
  16. CircleSector(A, E, G) → q
  17. CircleSector(A, G, D) → r
  18. Dilate(A, If[0 < i < 1, 1 - i], C) → A'
  19. Vector(A, A') → u
  20. Translate(q, u) → q'
  21. Translate(r, u) → r'
  22. CircleArc(A, E, G) → c_1
  23. CircleArc(A, G, D) → f_1

AI Drawing Prompt Reference

Draw a figure with two lines a and d intersected by a third line b. Take point A on line a and point B on line b, then rotate point B to get B'. Mark ∠BAB' as β. Draw line b and a circle e with center A. The intersection of line b and line d is point C, and draw a circle f with center C. The intersections of line a and circle e are D and E, and the intersections of line b and circle e are F and G. The intersections of circle f and line b are H and I, and the intersections of circle f and line d are J and K. Draw sectors C-K-I, C-I-J, C-J-H, C-H-K, A-E-G, and A-G-D, and perform scaling and translation operations to get sectors A-E-G' and A-G'-D'.
The prompt above was compiled from the original drawing commands and is for reference only.