GoGeometry 行动47:平行四边形动态几何演示
几何画板及绘图内容加载中,请稍等……
① 本范例动态展示了一个与平行四边形相关的几何问题,源自GoGeometry网站,通过可拖拽的交互图形直观呈现几何关系。② 核心数学概念涉及平行四边形性质、线段比例、角度关系以及切线等,并可能包含整数边长或指数运算的趣味设定。③ 作图要点:从构造摘要可见,使用了射线、旋转、直线、点、交点、线段、角、圆、位似、扇形、向量、平移、多边形、中点、垂线等GeoGebra命令,构建了丰富的辅助线与动态对象,如A、B、C、D等点以及多个圆和线段,支持实时修改与观察。④ 适合中学几何教学或自学,用于探索平行四边形相关定理,也可作为动态几何课件设计的参考范例。
GeoGebra 命令及参数
Ray(A, B) → fRotate(B, a°, A) → B'Ray(A, B') → gLine(B, g) → hPoint(g) → CLine(C, f) → iIntersect(h, i) → DSegment(C, D) → g_3Line(A, D) → t_1Segment(A, C) → f_3Angle(B, A, B') → αSegment(C, D) → jSegment(A, B) → kSegment(B, D) → lSegment(A, C) → mMin(m, k) → bCircle(C, (0.2 * b)) → dCircle(A, (0.2 * b)) → eCircle(B, (0.2 * b)) → pCircle(D, (0.2 * b)) → cIntersect(e, k, 1) → EIntersect(e, m, 1) → FIntersect(p, k, 1) → GIntersect(p, l, 1) → HIntersect(d, g, 2) → IRay(C, I) → qIntersect(c, h, 2) → JRay(D, J) → rIntersect(c, i, 2) → KRay(D, K) → sDilate(A, If[0 < o ≤ 1, 1 - o, 0], B) → A'Segment(A, A') → tRotate(E, If[1 < o ≤ 2, ((o - 1) * α), α], A) → E'CircleSector(A, E, E') → c_1Dilate(A, If[2 < o ≤ 3, 3 - o, 0], C) → A'_1Vector(A, A'_1) → uTranslate(c_1, u) → d_1Segment(A, A'_1) → f_1Dilate(C, If[3 < o ≤ 4, 4 - o, 0], D) → C'Vector(C, C') → vTranslate(d_1, v) → e_1Segment(C, C') → g_1Dilate(D, If[4 < o ≤ 5, 5 - o, 0], B) → D'Segment(D, D') → h_1Polygon(A, B, D, C) → poly1, a_1, b_1, d_2, c_2Dilate(A, If[5.5 < o ≤ 6.5, 6.5 - o, 0], C) → A'_2Vector(A, A'_2) → wTranslate(A, w) → A'_3Translate(A', w) → A''Dilate(A, If[6.5 < o ≤ 7.5, 7.5 - o, 0], B) → A'_4Vector(A, A'_4) → u_1Translate(A, u_1) → A'_5Translate(A'_1, u_1) → LRotate(D, If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], B) → D'_2Rotate(D', If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], B) → D''Rotate(C, If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], D) → C'_2Rotate(C', If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], D) → C''Rotate(A, If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], C) → A'_7Rotate(A'_1, If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], C) → MRotate(A, If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], A) → A'_8Rotate(A', If[6 < o ≤ 7, ((-(o - 6)) * π / 3), ((-π)) / 3], A) → A''_1Rotate(D, If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], D) → D'_3Rotate(D', If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], D) → D''_1Rotate(C, If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], C) → C'_3Rotate(C', If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], C) → C''_1Rotate(A, If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], A) → A'_9Rotate(A'_1, If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], A) → NRotate(A, If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], B) → A'_{10}Rotate(A', If[7 < o ≤ 8, ((o - 7) * π / 3), π / 3], B) → A''_2Line(A, D) → s_2Midpoint(A, D) → QRotate(A, If[16 < o ≤ 17, ((o - 16) * π), π], Q) → A'_{11}Midpoint(A, C) → ODilate(A, If[6 < o ≤ 7, 7 - o, 0], O) → A'_6Segment(A, A'_6) → i_1Rotate(A, If[7 < o ≤ 8, ((o - 7) * π), π], O) → A'_{12}Rotate(A'_6, If[7 < o ≤ 8, ((o - 7) * π), π], O) → PSegment(A'_{12}, P) → j_1Line(A, D) → k_1OrthogonalLine(B, k_1) → l_1Line(O, D) → m_1OrthogonalLine(B, m_1) → n_1Intersect(m_1, n_1) → RDilate(O, If[8 < o ≤ 9, 9 - o, 0], D) → O'Segment(O, O') → p_1Dilate(B, If[9 < o ≤ 10, 10 - o, 0], R) → B'_1Segment(B, B'_1) → q_1Angle(B, R, D) → βDilate(A, If[10 < o ≤ 11, 11 - o, 0], R) → A'_{13}Segment(A, A'_{13}) → r_1Angle(B, A, R) → γRotate(A, If[11.5 < o ≤ 12.5, ((-(o - 11.5)) * γ), (-γ)], A) → A'_{14}Rotate(A'_{13}, If[11.5 < o ≤ 12.5, ((-(o - 11.5)) * γ), (-γ)], A) → SSegment(A'_{14}, S) → s_1Line(O, D) → f_2Circle(D, 2) → e_2Circle(O, 2) → g_2Intersect(e_2, f_2, 2) → TIntersect(g_2, f_2, 1) → URay(D, T) → h_2Ray(O, U) → i_2Polygon(R, B, D, C, A) → poly2, r_2, b_2, d_3, c_3, a_2Polygon(R, B, A) → poly3, a_3, r_3, b_3