圆的切线 by dsyddall

GeoGebra 命令及参数

1. Intersect(xAxis, yAxis) → A
2. Point(yAxis) → B
3. Circle(A, B) → c
4. Tangent(E, c) → b, e
5. Intersect(c, e, 1) → G
6. Point(c) → H
7. Point(c) → C
8. Point(c) → D
9. Angle(E, G, A) → α
10. Point(b) → Q
11. Vector(P, Q) → a
12. Segment(G, A) → d
13. Intersect(c, b, 1) → R
14. Intersect(c, e, 1) → S
15. Distance(R, E) → distanceRE
16. Distance(E, S) → distanceES
17. Segment(A, R) → f
18. Angle(A, R, E) → β