几何变换与圆弧构造:旋转/镜像生成多边形角度结构
几何画板及绘图内容加载中,请稍等……
本例展示如何通过旋转、镜像、圆与圆弧等操作,在平面几何中构造出由若干角度与边段关系支撑的图形结构。核心数学概念包括几何变换(Rotate、Mirror、Dilate、Translate)、圆与圆弧(Circle、CircleArc)、直线与交点(Line、Intersect、OrthogonalLine)、以及角度度量(Angle)与线段约束(Segment)等。作图要点为:利用 Rotate 对关键点/向量进行旋转,再用 Mirror 进行对称复制,同时借助 Circle 与 CircleArc 生成圆弧边界;通过 Line、Ray 与 OrthogonalLine 建立辅助直线与垂线关系,并使用 Intersect 计算关键交点(如 C、O、H、D 等对象);最后用 Angle 标注并校验角度关系,并可结合 Vector、Dilate、Translate 调整位置与尺度。该范例适合中学几何教学中的作图活动、竞赛几何训练与几何变换复习,也适合作为 GeoGebra 几何建模与可视化的示例。
GeoGebra 命令及参数
Rotate(N, If[1 < a ≤ 2, (-(a - 1)), -1], M) → N'CircleArc(M, N', N) → cMirror(c, yAxis) → c'Rotate(C, If[1 < a ≤ 2, (-(a - 1)), -1], N') → C'Rotate(C', -2, M) → C''_{1}Rotate(C''_{1}, -2, M) → OLine(O, C''_{1}) → tLine(M, t) → g_1Intersect(c', g_1) → H,Line(C', C''_{1}) → hLine(M, h) → iIntersect(c, i, 1) → DAngle(D, M, H) → βRotate(D, If[5 < a ≤ 6, ((a - 5) * β), β], M) → D'Mirror(D', M) → D''Segment(D', D'') → s_1Circle(H, s_1 / 7) → t_1Intersect(t_1, s_1, 1) → RMirror(H, R) → H'Mirror(R, H') → R'Mirror(H', R') → H''Mirror(C', yAxis) → C''Line(M, C'') → n_2OrthogonalLine(C'', n_2) → p_2Line(M, p_2) → q_2Point(q_2) → USegment(((-r), 0), (r, 0)) → fRotate(B, If[7.5 < a ≤ 8.5, ((-(a - 7.5)) * 2), -2], (0, 0)) → B'_{2}Line((0, 0), B'_{2}) → bOrthogonalLine(B'_{2}, b) → f_1Circle((0, 0), r) → d_1Vector(I, J) → vRotate((r, 0), 1, (0, 0)) → KRotate((r, 0), 3, (0, 0)) → LMirror(K, y = 0) → K'Dilate(M, If[0 < a ≤ 1, 1 - a, 0], N) → M'Vector(M, M') → wTranslate(f, w) → f'_{2}Mirror(N', yAxis) → N''Mirror(A, yAxis) → A'Circle(N', r - c) → dSegment(N', C') → gMirror(N', yAxis) → N''_{1}Segment(N''_{1}, C'') → g'Rotate(C', -1, M) → C''_{2}Angle(B, M, D) → αRotate(B, If[2 < a ≤ 3, ((a - 2) * α), α], M) → B'Mirror(B', M) → B''Segment(B'', B') → jDilate(M, If[3 < a ≤ 4, 4 - a, 0], C''_{2}) → M'_{1}Vector(M, M'_{1}) → uTranslate(B'', u) → B'''Translate(B', u) → B''_{1}Segment(B''', B''_{1}) → j'Rotate(C''_{2}, If[4 < a ≤ 5, a - 4, 1], M) → ERotate(C''_{2}, If[4 < a ≤ 5, (-(a - 4)), -1], M) → FCircleArc(M, C''_{2}, E) → eCircleArc(M, F, C''_{2}) → kCircle(E, j / 2 - e) → pLine(M, E) → lOrthogonalLine(E, l) → mRotate(M, ((-pi)) / 2, E) → M'_{2}Ray(E, M'_{2}) → nIntersect(p, n, 1) → GRotate(M, pi / 2, E) → M'_{3}Segment(E, G) → qLine(M, C''_{2}) → sMirror(E, s) → E'Mirror(G, s) → G'Segment(E', G') → q'Rotate(C''_{1}, -1, M) → PSegment(D', D'') → h_1Dilate(M, If[6 < a ≤ 7, 7 - a, 0], P) → M'_{4}Vector(M, M'_{4}) → u_1Translate(D', u_1) → D''_{1}Translate(D'', u_1) → D'''Segment(D''_{1}, D''') → i_1Rotate(P, If[7 < a ≤ 8, a - 7, 1], M) → P'Line(M, P) → j_1Mirror(P', j_1) → P''CircleArc(M, P, P') → c_1CircleArc(M, P'', P) → e_1Circle(P', h_1 / 2 - c_1) → k_1Circle(P'', h_1 / 2 - c_1) → p_1Line(M, P') → l_1OrthogonalLine(P', l_1) → m_1Rotate(M, ((-pi)) / 2, P') → M'_{5}Ray(P', M'_{5}) → n_1Intersect(k_1, n_1) → Q,Segment(P', Q) → q_1Mirror(Q, j_1) → Q'Segment(P'', Q') → r_1Mirror(R', H'') → R''Mirror(H'', R'') → H'''Mirror(R'', H''') → R'''Dilate(H, If[8 < a ≤ 9, 9 - a, 0], R) → H'_{1}Segment(H, H'_{1}) → a_1Rotate(H, If[9 < a ≤ 10, ((a - 9) * pi), pi], R) → H'_{2}Segment(R, H'_{2}) → b_1Rotate(R, If[10 < a ≤ 11, ((a - 10) * pi), pi], H') → R'_{1}Segment(H', R'_{1}) → f_2Rotate(H', If[11 < a ≤ 12, ((a - 11) * pi), pi], R') → H''_{1}Segment(R', H''_{1}) → g_2Rotate(R', If[12 < a ≤ 13, ((a - 12) * pi), pi], H'') → R''_{1}Segment(H'', R''_{1}) → h_2Rotate(H'', If[13 < a ≤ 14, ((a - 13) * pi), pi], R'') → H'''_{1}Segment(R'', H'''_{1}) → i_2Rotate(R'', If[14 < a ≤ 15, ((a - 14) * pi), pi], H''') → R'''_{1}Segment(H''', R'''_{1}) → j_2Line(M, C'') → k_2Angle(U, M, H'') → γDilate(H'', If[15.5 < a ≤ 16.5, 16.5 - a, 0], C'') → H'''_{2}Vector(H'', H'''_{2}) → v_1Dilate(R', If[15.5 < a ≤ 16.5, 16.5 - a, 0], C'') → R''_{2}Vector(R', R''_{2}) → w_1Translate(R', w_1) → R''_{3}Translate(H''_{1}, w_1) → SSegment(R''_{3}, S) → l_2Rotate(R''_{3}, If[15.5 < a ≤ 16.5, ((-(a - 15.5)) * γ), (-γ)], R''_{2}) → TRotate(S, If[15.5 < a ≤ 16.5, ((-(a - 15.5)) * γ), (-γ)], R''_{2}) → S'Segment(T, S') → m_2Rotate(C'', If[16.5 < a ≤ 17.5, ((a - 16.5) * 0.28), 0.28], M) → C'''CircleArc(M, C'', C''') → c_2Circle(C''', (0.14 * s_1) - c_2) → d_2Line(C''', M) → r_2OrthogonalLine(C''', r_2) → s_2Rotate(M, ((-pi)) / 2, C''') → M'_{6}Ray(C''', M'_{6}) → t_2Intersect(d_2, t_2, 1) → VSegment(C''', V) → a_2If(8 < a ≤ 15, 0.75, 0.25) → o_1
AI 绘图提示语参考
在平面内构造一个以旋转、镜像与圆弧生成的几何配置:先给定中心点M及一条基准线,通过围绕M的旋转得到新点N′,再以M、N′、N确定一段圆弧c,随后把该圆弧关于y轴镜像得到c′;再把以相关圆弧产生的点与镜像点继续用以M为中心的旋转得到更多圆弧交互结构,并引入多条辅助直线以与圆弧求交,得到关键交点H与D;计算从D指向M与H的夹角并用该角量生成另一点D′,再用关于M与y轴的镜像与连线得到对称段与圆(如以H为圆心、由对称段确定半径),最后补充若干与圆、垂线、旋转构成的角度标注(如β与α)来完成整体结构。
以上提示语为根据原始绘图命令整理而来,仅供参考。