三角形内角和 by Guillermo Bautista

GeoGebra 命令及参数

1. Polygon(A, B, C) → poly1, c, a, b
2. Angle(poly1) → α, β, γ
3. Midpoint(c) → D
4. Rotate(A, δ, D) → A'
5. Rotate(B, δ, D) → B'
6. Rotate(C, δ, D) → C'
7. Polygon(A', B', C') → poly1', c', a', b'
8. Angle(poly1') → ε, ζ, η
9. Midpoint(b) → E
10. Rotate(A, (-δ), E) → A'_1
11. Rotate(B, (-δ), E) → B'_1
12. Rotate(C, (-δ), E) → C'_1
13. Polygon(A'_1, B'_1, C'_1) → poly1'_1, c'_1, a'_1, b'_1
14. Angle(poly1'_1) → θ, ι, κ