动态几何图形演示
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,通过可调节的参数展示图形变换过程;②涉及的核心数学概念包括几何变换(旋转、缩放)、解析几何、向量与轨迹;③作图要点提炼自 GeoGebra 命令:Rotate(旋转)、Dilate(缩放)、Polygon(多边形)、Midpoint(中点)、CircleArc(圆弧)、Point(点)、Segment(线段)、Intersect(交点)、Circle(圆)、Vector(向量)、Line(直线)、Angle(角度)、Mirror(镜像)、CircleSector(圆扇形)、Ray(射线)、OrthogonalLine(垂线)、Translate(平移);④适合高中及以上学生及数学爱好者用于理解几何变换与动态几何的原理,可作为教学演示或探究工具。
GeoGebra 命令及参数
Rotate(A, If[1 < e ≤ 2, ((-(e - 1)) * π / 2), -1.5707963267948966], B_2) → A'_1Dilate(A, If[0 < e ≤ 1, 1 - e, 0], B_2) → A'Rotate(A', If[1 < e ≤ 2, ((-(e - 1)) * π / 2), -1.5707963267948966], B_2) → A''Polygon(A, B_2, 4) → poly1, a, b, c, d, C, DMidpoint(A, C) → VCircleArc(V, C, D) → g_2Point(g_2) → BSegment(C, B) → j_1Segment(A, B) → nRotate(A'', If[2 < e ≤ 3, ((-(e - 2)) * π / 2), -1.5707963267948966], C) → A'''Rotate(A'_1, If[2 < e ≤ 3, ((-(e - 2)) * π / 2), -1.5707963267948966], C) → RSegment(R, A''') → f''Intersect(n, f'') → ZSegment(B, Z) → l_1Segment(A, A') → fSegment(A'_1, A'') → f'Segment(A, B_2) → gSegment(B_2, C) → hSegment(C, D) → iSegment(D, A) → jCircle(B_2, (0.15 * f)) → pCircle(C, Radius[p]) → kCircle(A, (0.1 * j)) → qCircle(D, (0.1 * j)) → rSegment(A, C) → lSegment(D, B_2) → mIntersect(r, j, 1) → FIntersect(r, m, 1) → GIntersect(r, i, 1) → HIntersect(k, i, 1) → IIntersect(k, l, 1) → JIntersect(k, h, 1) → KIntersect(p, h, 1) → LIntersect(p, m, 1) → MIntersect(p, g, 1) → NIntersect(q, g, 1) → OIntersect(q, l, 1) → PIntersect(q, j, 1) → QRotate(R, If[3 < e ≤ 4, ((-(e - 3)) * π / 2), -1.5707963267948966], D) → R'Rotate(A''', If[3 < e ≤ 4, ((-(e - 3)) * π / 2), -1.5707963267948966], D) → SSegment(R', S) → f'''Dilate(B_2, If[4 < e ≤ 5, 5 - e, 0], C) → B'Vector(B_2, B') → uDilate(C, If[6 < e ≤ 7, 7 - e, 0], D) → C'Vector(C, C') → vDilate(D, If[8 < e ≤ 9, 9 - e, 0], A) → D'Vector(D, D') → wDilate(B_2, If[18 < e ≤ 19, 19 - e, 0], C) → B'_1Dilate(B_2, If[18 < e ≤ 19, 19 - e, 0], A) → B'_2Dilate(B_2, If[18 < e ≤ 19, 19 - e, 0], D) → B'_3Vector(B_2, B'_1) → v_1Vector(B_2, B'_3) → w_1Vector(B_2, B'_2) → i_1Circle(A, n - j_1) → h_2Dilate(B, If[10 < e ≤ 11, 11 - e, 0], C) → W'Dilate(B_2, If[13 < e ≤ 14, 14 - e, 0], B) → B'_4Vector(B_2, B'_4) → u_1Line(B, f') → a_1Point(a_1) → UAngle(U, B, C) → αRotate(B, If[14 < e ≤ 15, ((-(e - 14)) * π / 2), ((-π)) / 2], B) → W'_2Rotate(W', If[14 < e ≤ 15, ((-(e - 14)) * π / 2), ((-π)) / 2], B) → W''Line(A, B_2) → h_1Angle(B, A, D) → βDilate(D, If[19 < e ≤ 20, 20 - e, 0], B) → D'_1Mirror(C, D) → C'_1Rotate(C, ((-π)) / 3, B_2) → C'_2Segment(B_2, C'_2) → f_1Segment(C, C'_2) → g_1Intersect(k, g_1, 1) → EIntersect(k, h) → T,CircleSector(C, T, E) → d_1Rotate(D, 15°, C) → D'_2Angle(D, C, D'_2) → γRay(C, D'_2) → k_1Rotate(C, (-(15°)), D) → C'_3Angle(C'_3, D, C) → δRay(D, C'_3) → m_1Intersect(k_1, m_1) → WRotate(B_2, If[10 < e ≤ 11, (((-π)) / 3 * (e - 10)), ((-π)) / 3], B_2) → A_1Rotate(C, If[10 < e ≤ 11, (((-π)) / 3 * (e - 10)), ((-π)) / 3], B_2) → C'_4Rotate(B_2, If[11 < e ≤ 12, (π / 3 * (e - 11)), π / 3], C) → B_1Rotate(C, If[11 < e ≤ 12, (π / 3 * (e - 11)), π / 3], C) → C'_5Rotate(E, If[12 < e ≤ 13, (((-π)) / 6 * (e - 12)), ((-π)) / 6], C) → E'Polygon(C, W, D) → poly2, d_2, c_2, w_2Polygon(A, W, D) → poly3, d_3, a_2, w_3Polygon(B_2, W, C) → poly4, c_3, b_2, w_4Polygon(A, B_2, W) → poly5, w_5, a_3, b_1Rotate(T, 15°, C) → T'Angle(T, C, T') → εRay(C, T') → q_1Dilate(C, If[21 < e ≤ 22, 22 - e, 0], D) → C'_8Vector(C, C'_8) → u_2Dilate(D, If[23 < e ≤ 24, 24 - e, 0], W) → D'_3Dilate(C, If[23 < e ≤ 24, 24 - e, 0], W) → C'_9Dilate(B_2, If[25 < e ≤ 26, 26 - e, 0], W) → G_1Dilate(A, If[25 < e ≤ 26, 26 - e, 0], W) → A'_2Rotate(B_2, If[26.75 < e ≤ 27.75, (π / 2 * (e - 26.75)), π / 2], B_2) → H_1Rotate(C'_2, If[26.75 < e ≤ 27.75, (π / 2 * (e - 26.75)), π / 2], B_2) → I_1Rotate(C, If[26.75 < e ≤ 27.75, (π / 2 * (e - 26.75)), π / 2], B_2) → C'_{10}Midpoint(D, R) → D_1Rotate(A, ((-π)) / 2, B_2) → A'_3Rotate(B_2, π / 2, A) → E_1Midpoint(A'_3, E_1) → F_1Segment(F_1, A) → n_1Segment(B_2, F_1) → r_1Point(a) → M_3Angle(A'_1, B_2, A) → ζAngle(D, A'_1, B_2) → ηAngle(B_2, A, D) → θAngle(M_3, D, A'_1) → κRotate(A'_1, (-(κ / 2)), D) → N_3Angle(N_3, D, A'_1) → ιRay(D, N_3) → sLine(A'_1, B_2) → tIntersect(s, t) → O_3Line(D, M_3) → n_4OrthogonalLine(O_3, n_4) → p_4Intersect(n_4, p_4) → P_3Angle(O_3, P_3, D) → λRotate(B_2, 45°, A) → Q_3Angle(B_2, A, Q_3) → μRay(A, Q_3) → q_4Circle(A, a / 6) → c_4Intersect(c_4, f) → R_3,Ray(D, O_3) → r_4Ray(A, P_3) → s_4Intersect(r_4, s_4) → S_3Circle(D, a / 6) → e_4Intersect(e_4, n_4, 2) → T_3Dilate(D, If[6 < e ≤ 7, 7 - e, 0], M_3) → D'_4Segment(D, D'_4) → t_4Polygon(A, B_2, 4) → poly6, p_1, s_1, t_1, c_1, C_1, J_1Dilate(D, If[7 < e ≤ 8, 8 - e, 0], O_3) → D'_5Dilate(D, If[7 < e ≤ 8, 8 - e, 0], O_3) → D'_6Segment(D, D'_6) → e_1Rotate(T_3, If[8 < e ≤ 9, ((e - 8) * κ / 2), κ / 2], D) → K_1CircleSector(D, T_3, K_1) → e_2Rotate(e_2, If[10 < e ≤ 11, ((e - 10) * κ / 2), κ / 2], D) → f_2Dilate(O_3, If[11 < e ≤ 12, 12 - e, 0], P_3) → L_1Segment(O_3, L_1) → i_2Dilate(A, If[13 < e ≤ 14, 14 - e, 0], P_3) → A'_4Segment(A, A'_4) → j_2Dilate(P_3, If[14 < e ≤ 15, 15 - e, 0], S_3) → M_1Dilate(O_3, If[14 < e ≤ 15, 15 - e, 0], S_3) → N_1Segment(P_3, M_1) → k_2Segment(O_3, N_1) → l_2Line(A, A'_1) → m_2Circle(A'_1, a / 6) → p_2Intersect(p_2, f'', 1) → O_1Circle(A'_1, a / 3) → q_2Intersect(q_2, m_2, 1) → P_1Rotate(O_1, If[16 < e ≤ 17, ((e - 16) * π / 4), π / 4], A'_1) → Q_1CircleSector(A'_1, O_1, Q_1) → r_2Dilate(A'_1, If[16 < e ≤ 17, 17 - e, 0], P_1) → R_1Segment(A'_1, R_1) → n_2Rotate(r_2, If[18 < e ≤ 19, ((e - 18) * π / 4), π / 4], A'_1) → s_2Dilate(A'_1, If[20 < e ≤ 21, 21 - e, 0], S_3) → S_1Vector(A'_1, S_1) → v_2Translate(s_2, v_2) → t_2Line(A'_1, e_1) → f_3Point(f_3) → T_1Angle(T_1, A'_1, R_1) → τRotate(t_2, If[20 < e ≤ 21, ((e - 20) * (-τ)), (-τ)], S_1) → e_3