圆的切线性质探究

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Tangent(B, c) → a,
3. Point(c) → C
4. Tangent(C, c) → b,
5. Intersect(a, b) → D
6. Segment(C, A) → d
7. Segment(A, B) → e
8. Segment(A, D) → f
9. Segment(C, A) → g
10. Polygon(C, A, D) → poly1, d_1, c_1, a_1
11. Angle(poly1) → α, β, γ
12. Distance(C, D) → distanceCD
13. Distance(B, D) → distanceBD
14. Angle(D, B, A) → δ