动态几何问题演示 by Tim Brzezinski
几何画板及绘图内容加载中,请稍等……
①本范例动态演示了由 Antonio Gutierrez 在 Twitter 上提出的一个几何问题;②涉及核心数学概念包括极限、函数图像、随机变量、条件概率和参数曲线;③作图要点:运用了 Midpoint(中点)、Segment(线段)、Circle(圆)、OrthogonalLine(垂线)、Intersect(交点)、Ray(射线)、Point(点)、Angle(角度)、Rotate(旋转)、Polygon(多边形)、Line(直线)、Min(最小值)、Dilate(缩放)、CircleSector(扇形)、Vector(向量)、Translate(平移)等 GeoGebra 命令与对象;④适合高中及以上数学学习者,用于理解复杂几何问题的动态变化过程。
GeoGebra 命令及参数
Midpoint(A, B) → HSegment(A, H) → rCircle(A, 2) → cSegment(A, B) → fOrthogonalLine(A, f) → gIntersect(c, g, 2) → CRay(A, C) → hPoint(h) → DSegment(D, B) → iOrthogonalLine(A, i) → mIntersect(m, i) → GAngle(G, H, A) → βRotate(G, β / 2, H) → G'Ray(H, G') → tSegment(G, H) → sSegment(A, G) → qIntersect(q, t) → IMidpoint(H, I) → JSegment(H, J) → i_1Segment(H, I) → f_1Segment(G, B) → pSegment(D, G) → nSegment(A, D) → jPolygon(A, B, D) → t1, d, a, bLine(B, A) → kCircle(A, 2) → eIntersect(e, k) → E, FRay(A, F) → lAngle(D, A, F) → αMin({n, p, q, r, f_1, s, i_1}) → oAngle(G, H, G') → γDilate(A, If[0 < u ≤ 1, 1 - u, 0], H) → A'Segment(A, A') → g_1Rotate(A, If[1 < u ≤ 2, ((-(u - 1)) * π), (-π)], H) → A'_1Rotate(A', If[1 < u ≤ 2, ((-(u - 1)) * π), (-π)], H) → A''Segment(A'_1, A'') → h_1Dilate(H, If[2 < u ≤ 3, 3 - u, 0], G) → H'Segment(H, H') → j_1Dilate(H, If[3 < u ≤ 4, 4 - u, 0], J) → H'_1Segment(H, H'_1) → k_1Circle(H, (0.45 * o)) → c_1Segment(G, H) → l_1Line(J, H) → m_1Intersect(c_1, m_1) → K, LIntersect(c_1, l_1) → M,Rotate(M, If[5 < u ≤ 6, ((u - 5) * γ), γ], H) → M'CircleSector(H, M, M') → d_1Rotate(d_1, If[7 < u ≤ 8, ((u - 7) * γ), γ], H) → e_1Midpoint(A, G) → NDilate(H, If[8 < u ≤ 9, 9 - u, 0], N) → H'_2Vector(H, H'_2) → vTranslate(e_1, v) → p_1Rotate(p_1, If[9 < u ≤ 10, ((-(u - 9)) * π / 2), ((-π)) / 2], N) → q_1Dilate(N, If[10 < u ≤ 11, 11 - u, 0], A) → N'Vector(N, N') → wTranslate(q_1, w) → r_1Dilate(A, If[11 < u ≤ 12, 12 - u, 0], G) → A'_2Segment(A, A'_2) → n_1Circle(G, (0.45 * o)) → s_1Intersect(s_1, i, 2) → ORotate(O, If[12.5 < u ≤ 13.5, ((-(u - 12.5)) * π / 2), ((-π)) / 2], G) → D'CircleSector(G, D', O) → t_1Rotate(t_1, If[14.5 < u ≤ 15.5, ((-(u - 14.5)) * π / 2), ((-π)) / 2], G) → c_2Rotate(A'_1, If[16 < u ≤ 17, ((u - 16) * (π - β)), π - β], H) → PRotate(A'', If[16 < u ≤ 17, ((u - 16) * (π - β)), π - β], H) → A'''Segment(P, A''') → a_1