纸折叠三等分角度
几何画板及绘图内容加载中,请稍等……
①本范例演示通过纸折叠实现角度三等分的几何作图方法;②涉及核心数学概念包括三角形、角度、几何变换与作图原理;③构造过程中运用了点、射线、圆、旋转、角度测量、交点、角平分线、多边形、距离计算、扇形、缩放、向量、平移、直线、线段等 GeoGebra 命令与对象;④适合高中数学教学或几何爱好者探索几何作图技巧。
GeoGebra 命令及参数
Point(yAxis) → CPoint(yAxis) → ARay(A, C) → gPoint(g) → DCircle(A, (0.5 * Distance[A, D])) → d_3Point(xAxis) → BRotate(B, (a * π / 180), A) → B'Ray(A, B') → hRay(A, B) → fAngle(B, A, B') → αRotate(B, α / 3, A) → B'_1Angle(B, A, B'_1) → βRotate(B'_1, α / 3, A) → EAngle(B'_1, A, E) → γRay(A, B'_1) → kRay(A, E) → lIntersect(i, k) → FIntersect(g, yAxis) → GIntersect(g, yAxis) → HIntersect(j, g) → IIntersect(h, j) → JLineBisector(A, F) → mIntersect(m, f) → KIntersect(m, g) → LPolygon(L, A, K) → t1, k_1, l_1, a_1Polygon(K, F, L) → t2, l_2, k_2, f_1Intersect(k_2, h) → MIntersect(j, m) → NDistance(I, N) → distanceINDistance(N, M) → distanceNMDistance(A, D) → cCircle(A, (0.3 * c)) → dIntersect(g, k_1) → OIntersect(g, k_1) → PIntersect(g, yAxis) → QIntersect(g, yAxis) → RIntersect(d, g) → S,Rotate(S, If[0 < b ≤ 1, (π / 2 * b), π / 2], A) → S'CircleSector(A, S, S') → eDilate(A, If[2 < b ≤ 3, 3 - b, 0], D) → A'Vector(A, A') → uTranslate(e, u) → e'Line(A, K) → nSegment(A, A') → pDilate(D, If[4 < b ≤ 5, 5 - b, 0], I) → D'Vector(D, D') → vTranslate(e', v) → e''Segment(D, D') → qRotate(A, If[5 < b ≤ 6, ((b - 5) * π), π], D) → A'_1Rotate(A', If[5 < b ≤ 6, ((b - 5) * π), π], D) → A''Segment(A'_1, A'') → p'Line(A, D) → rCircle(I, 2) → sIntersect(s, r, 2) → TRay(I, T) → tSegment(D, A') → g_1Segment(D, A) → h_1Intersect(i, m) → UIntersect(l, j) → VLine(L, U) → j_1Dilate(L, If[6 < b ≤ 7, 7 - b, 0], N) → L'Segment(L, L') → i_1Distance(I, i_1) → distanceIi1Distance(M, i_1) → distanceMi1Segment(A, K) → m_1Dilate(N, If[7 < b ≤ 8, 8 - b, 0], U) → N'Segment(N, N') → n_1Dilate(U, If[8 < b ≤ 9, 9 - b, 0], K) → U'Segment(U, U') → p_1Circle(K, 2) → d_1Circle(N, 2) → e_1Circle(A, 2) → q_1Intersect(q_1, n) → W, ZIntersect(d_1, n) → A_1, B_1Intersect(e_1, j) → C_1, D_1Ray(A, W) → r_1Ray(K, B_1) → s_1Ray(N, D_1) → t_1Circle(I, 2) → c_2Intersect(c_2, j) → E_1, F_1Ray(I, E_1) → f_2Segment(I, N) → g_2Dilate(I, If[9 < b ≤ 10, 10 - b, 0], N) → I'Dilate(A, If[9 < b ≤ 10, 10 - b, 0], K) → A'_2Segment(I, I') → h_2Segment(A, A'_2) → i_2Angle(M, N, I) → δAngle(F, K, A) → εRotate(I, If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], N) → I'_1Rotate(I', If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], N) → I''Segment(I'_1, I'') → j_2Rotate(A, If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], K) → A'_3Rotate(A'_2, If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], K) → G_1Segment(A'_3, G_1) → m_2Rotate(A, If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], K) → A'_4Rotate(A'_2, If[10 < b ≤ 11, ((-(b - 10)) * ε), (-ε)], K) → H_1Angle(F, L, A) → ζCircle(L, 2) → d_2Intersect(d_2, t) → I_1, J_1Segment(I, L) → n_2Ray(L, J_1) → p_2Rotate(I, If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → I'_2Rotate(L, If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → L'_1Segment(I'_2, L'_1) → q_2Rotate(A'_1, If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → K_1Rotate(A'', If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → A'''Segment(K_1, A''') → p''Rotate(A, If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → A'_5Rotate(A', If[11 < b ≤ 12, ((b - 11) * ζ), ζ], L) → A''_1Segment(A'_5, A''_1) → p'_1Intersect(d, y = y(A)) → O_1, P_1Intersect(d_3, h) → L_1,CircleSector(A, P_1, L_1) → e_2Line(A, U) → r_2Line(A, F) → s_2Circle(U, 2) → t_2Circle(F, 2) → c_3Intersect(t_2, r_2, 2) → M_1Intersect(c_3, s_2) → N_1, Q_1Ray(U, M_1) → a_2Ray(F, Q_1) → b_2Dilate(A, If[14 < b ≤ 15, 15 - b, 0], U) → A'_6Dilate(A, If[15 < b ≤ 16, 16 - b, 0], F) → A'_7Segment(A, A'_6) → g_3Segment(A, A'_7) → f_3Rotate(L_1, If[17 < b ≤ 18, ((-(b - 17)) * α / 3), ((-α)) / 3], A) → R_1CircleSector(A, R_1, L_1) → e_3Rotate(e_3, If[19 < b ≤ 20, ((-(b - 19)) * α / 3), ((-α)) / 3], A) → h_3Rotate(h_3, If[21 < b ≤ 22, ((-(b - 21)) * α / 3), ((-α)) / 3], A) → k_3