周长与面积基础回顾

GeoGebra 命令及参数

1. Polygon(A, B, C) → t1, c, a, b
2. If(d ≤ 3, Translate[B, Vector[(d / 3 * Vector[X])]], Translate[B, Vector[X]]) → E
3. If(d ≤ 3, Translate[C, Vector[(d / 3 * Vector[X])]], Translate[C, Vector[X]]) → F
4. If(d ≤ 3, Translate[A, Vector[(d / 3 * Vector[X])]], Translate[A, Vector[X]]) → D
5. Polygon(D, E, F) → t2, f, d_1, e
6. Centroid(t2) → G
7. If(d > 3 ∧ d < 7, Polygon[Rotate[D, (π / 4 * (d - 3)), G], Rotate[E, (π / 4 * (d - 3)), G], Rotate[F, (π / 4 * (d - 3)), G]], If[d ≥ 7, Polygon[Rotate[D, π, G], Rotate[E, π, G], Rotate[F, π, G]]]) → t3
8. Centroid(t1) → H
9. Midpoint(a) → I
10. Rotate(H, π, I) → H'
11. If(d ≥ 7, Translate[t3, Vector[((d - 7) / 3 * Vector[G, H'])]]) → t4
12. Segment(B, C) → g
13. Rotate(A, π, I) → A'
14. Polygon(A, B, A', C) → q1, a_1, b_1, a', c_1
15. Rotate(A, π, I) → A'_1