坐标平面上的平行与垂直线作图

GeoGebra 命令及参数

1. Random(-9, 9) → a
2. Random(-9, 9) → b
3. Sequence(i, i, b + 1, 9, 1) → l4
4. Sequence(i, i, -9, b - 1, 1) → l3
5. Union(l3, l4) → yList
6. Sequence(i, i, a + 1, 9, 1) → l2
7. Sequence(i, i, -9, a - 1, 1) → l1
8. Union(l1, l2) → xList
9. RandomElement(xList) → c
10. RandomElement(yList) → d
11. Line(B, A) → f
12. Line(C, D) → g
13. Random(1, 2) → n
14. If(n ≟ 1, "∥", "⟂") → text1
15. If(y(B) > y(A), (x(B), y(A)), (x(A), y(B))) → E
16. Polygon(A, E, B) → t1, b_1, a_1, e_1
17. If(y(D) > y(C), (x(D), y(C)), (x(C), y(D))) → F
18. Polygon(D, F, C) → t2, c_1, d_1, f_1
19. Segment(A, E) → j
20. Segment(E, B) → k
21. Segment(D, F) → l
22. Segment(F, C) → m
23. Slope(f) → o
24. Slope(g) → p
25. If(c1, "√", "X") → text2
26. If(c2, "√", "X") → text4
27. Textfield(q) → InputBox1
28. Textfield(r) → InputBox2
29. If(c3, "√", "X") → text5