三角形上的正方形与平行四边形 by Doug Kuhlmann
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这个范例展示了在三角形上构造正方形和平行四边形的过程。核心概念包括几何构造、多边形和线段。通过使用GeoGebra命令如Polygon、Segment、If等,可以动态地调整三角形的边长,观察正方形和平行四边形的变化。适合初中和高中学生学习几何构造和变换。
GeoGebra 命令及参数
Polygon(B, A, 4) → poly3, r, s, t, a, H, ISegment(A, B) → fSegment(B, C) → gSegment(C, A) → hPolygon(C, B, 4) → poly1, i, j, k, l, D, EPolygon(A, C, 4) → poly2, m, n_1, p, q, F, GIf(t1 ≤ 1, Segment[B, B + (t1 * (D - B))], If[t1 ≤ 2, Segment[D, D + ((t1 - 1) * (E - D))], Segment[E, E + ((t1 - 2) * (C - E))]]) → eIf(t1 ≤ 1, Segment[B, B + (t1 * (D - B))], If[t1 ≤ 2, Segment[D, D + ((t1 - 1) * (E - D))], Segment[E, E + ((t1 - 2) * (C - E))]]) → f_1If(t2 ≤ 1, Segment[C, C + (t2 * (F - C))], If[t2 ≤ 2, Segment[F, F + ((t2 - 1) * (G - F))], Segment[G, G + ((t2 - 2) * (A - G))]]) → i_1If(t3 ≤ 1, Segment[A, A + (t3 * (H - A))], If[t3 ≤ 2, Segment[H, H + ((t3 - 1) * (I - H))], Segment[I, I + ((t3 - 2) * (B - I))]]) → g_1Line(E, n_1) → bLine(F, e) → cIntersect(b, c) → JLine(H, i_1) → dLine(G, s) → h_1Intersect(d, h_1) → KLine(I, j) → j_1Line(D, g_1) → k_1Intersect(k_1, j_1) → LSegment(E, E + (t4 * (J - E))) → l_1Segment(F, F + (t4 * (J - F))) → m_1Segment(G, G + (t5 * (K - G))) → p_1Segment(H, H + (t5 * (K - H))) → q_1Segment(I, I + (t6 * (L - I))) → r_1Segment(D, D + (t6 * (L - D))) → s_1Ray(L, B) → t_1Ray(K, A) → a_1Intersect(t_1, a_1) → MSegment(K, K + (t7 * (M - K))) → b_1Segment(J, J + (t7 * (M - J))) → c_1Segment(L, L + (t7 * (M - L))) → d_1