三角形的内切圆 by Heather Pierce

GeoGebra 命令及参数

1. Segment(A, B) → f
2. Segment(B, C) → g
3. Segment(C, A) → h
4. AngularBisector(C, A, B) → i
5. AngularBisector(A, B, C) → j
6. AngularBisector(B, C, A) → k
7. Intersect(i, g) → X
8. Intersect(j, h) → Y
9. Intersect(k, f) → Z
10. If(a < 1, Segment[A, (x(A) + (a * (x(X) - x(A))), y(A) + (a * (y(X) - y(A))))], Segment[A, X]) → l
11. If(2 < a < 3, Segment[C, (x(C) + ((a - 2) * (x(Z) - x(C))), y(C) + ((a - 2) * (y(Z) - y(C))))], a ≥ 3, Segment[C, Z]) → n
12. If(1 < a < 2, Segment[B, (x(B) + ((a - 1) * (x(Y) - x(B))), y(B) + ((a - 1) * (y(Y) - y(B))))], a ≥ 2, Segment[B, Y]) → m
13. Intersect(l, n) → I
14. OrthogonalLine(I, h) → p
15. Intersect(p, h) → D
16. If(3 < a < 4, Circle[I, (x(I) + ((a - 3) * (x(D) - x(I))), y(I) + ((a - 3) * (y(D) - y(I))))], a ≟ 4, Circle[I, D]) → c