定位圆的切线

GeoGebra 命令及参数

1. Circle(B, J) → eq1
2. Point(eq1) → A
3. Textfield(r) → InputBox1
4. Line(C, D) → f
5. Intersect(x = x(B), y = y(A)) → F
6. Polygon(B, F, A) → t1, a, b, f_1
7. IsTangent(f, eq1) → e
8. Line(B, A) → g
9. Point(f) → G
10. Polygon(G, H, I) → t2, i, g_1, h_1
11. Segment(G, H) → j
12. Segment(H, I) → l
13. Segment(A, F) → m
14. Segment(F, B) → p
15. Angle(A, F, B) → α
16. Angle(I, H, G) → β
17. Segment(A, B) → q
18. If(e ≟ true, "Line is tangent to circle!", "") → text5
19. Angle(g, f) → γ