等腰三角形底角性质的动态探究

GeoGebra 命令及参数

1. PointIn(b) → B
2. PointIn(c) → C
3. Polygon(A, B, C) → t3, c_1, a, b_1
4. Intersect(a, OrthogonalLine[A, a, space]) → D
5. Segment(A, D) → f
6. Rotate(CircleSector[C, C + (0.7 * UnitVector[Segment[C, A]]), D, xOyPlane], (180° * t2), f) → d
7. Rotate(CircleSector[B, B + (0.7 * UnitVector[Segment[B, A]]), D], (-180° * t1), f) → e
8. Rotate(Polygon[{A, D, C}], (180° * t2), f) → t4
9. Rotate(Polygon[{A, D, B}], (-180° * t1), f) → t5
10. Angle(C, D, A) → α