平行四边形中的奇妙现象
几何画板及绘图内容加载中,请稍等……
本范例展示了当在平行四边形的两边上添加平行线段时,所发生的动态且可修改的关系。核心数学概念包括平行线、等边三角形和整数。通过使用GeoGebra命令如Line、Rotate、Segment等进行构造。适合初中及以上学生学习几何作图和变换。
GeoGebra 命令及参数
Line(A, B) → r_2Rotate(B, a°, A) → B'Ray(A, B') → gLine(B, g) → hPoint(g) → CSegment(A, C) → p_1Point(p_1) → TRay(A, B) → fLine(C, f) → iIntersect(h, i) → DSegment(C, D) → q_1Line(T, q_1) → t_1Point(q_1) → ULine(U, p_1) → s_1Intersect(t_1, s_1) → ZLine(C, Z) → g_2Segment(T, C) → j_1Segment(A, T) → i_1Segment(U, D) → l_1Segment(C, U) → k_1Angle(B, A, B') → αSegment(C, D) → jSegment(A, B) → kSegment(B, D) → lSegment(A, C) → mMin({i_1, j_1, k_1, l_1}) → bCircle(C, (0.3 * b)) → dCircle(A, (0.35 * b)) → eCircle(B, (0.4 * b)) → pCircle(D, (0.3 * 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) → LIntersect(d, i) → M, NIntersect(d, g) → O, PAngle(A, C, N) → βRotate(N, If[6.5 < o ≤ 7.5, ((-(o - 6.5)) * β), (-β)], C) → N'Dilate(C, If[7.5 < o ≤ 8.5, 8.5 - o, 0], B) → C'_1Vector(C, C'_1) → v_1Segment(D, B) → r_1Segment(A, B) → f_2Intersect(f_2, s_1) → VIntersect(t_1, r_1) → WSegment(D, V) → i_2Segment(A, W) → j_2Intersect(g_2, r_2) → A_1Dilate(T, If[6.5 < o ≤ 7.5, 7.5 - o, 0], W) → T'Segment(T, T') → m_1Dilate(U, If[7.5 < o ≤ 8.5, 8.5 - o, 0], Z) → U'Segment(U, U') → n_1Dilate(Z, If[8.5 < o ≤ 9.5, 9.5 - o, 0], V) → Z'Segment(Z, Z') → h_2Dilate(A, If[9.5 < o ≤ 10.5, 10.5 - o, 0], T) → A'_6Vector(A, A'_6) → w_1Translate(c_1, w_1) → e_2Dilate(D, If[10.5 < o ≤ 11.5, 11.5 - o, 0], U) → C'_2Vector(D, C'_2) → u_2Dilate(T, If[10.5 < o ≤ 11.5, 11.5 - o, 0], Z) → T'_1Vector(T, T'_1) → v_2Translate(e_2, v_2) → k_2Intersect(g_2, j_2) → QDilate(C, If[11.5 < o ≤ 12.5, 12.5 - o, 0], A_1) → C'_3Segment(C, C'_3) → l_2Dilate(A, If[12.5 < o ≤ 13.5, 13.5 - o, 0], Q) → A'_7Segment(A, A'_7) → m_2Dilate(Q, If[13.5 < o ≤ 14.5, 14.5 - o, 0], W) → Q'Segment(Q, Q') → n_2Dilate(D, If[14.5 < o ≤ 15.5, 15.5 - o, 0], Q) → D'_1Segment(D, D'_1) → p_2Intersect(l_2, m_2) → RDilate(Q, If[15.5 < o ≤ 16.5, 16.5 - o, 0], V) → Q'_1Segment(Q, Q'_1) → q_2