SAS几何作图练习1
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①本范例演示了使用SAS(边角边)判定三角形全等的几何作图过程;②涉及的核心数学概念包括全等三角形判定、角度测量、线段复制与变换;③作图要点——从下方『构造摘要』提炼用到了Segment(线段)、Angle(角度)、Line(直线)、Polygon(多边形)、Mirror(镜像)、Rotate(旋转)等GeoGebra命令及对象A, B, c, C, b, α, a, D_1, E_1等;④适合初中数学几何单元教学或学生自主探究三角形全等性质。
GeoGebra 命令及参数
Segment(A, B) → cSegment(A, C) → bAngle(B, A, C) → αSegment(C, B) → aLine(D_1, E_1) → d_1Polygon(A, B, C) → poly1, c_1, a_1, b_1Mirror(A, d_1) → A'Mirror(B, d_1) → B'Mirror(C, d_1) → C'Polygon(A', B', C') → poly1', c', a', b'Mirror(A, d_1) → A'_1Mirror(C, d_1) → F_2Segment(A'_1, F_2) → e_1Mirror(A, d_1) → D_2Mirror(B, d_1) → B'_1Segment(D_2, B'_1) → f_1Mirror(C, d_1) → C'_2Mirror(B, d_1) → E_2Segment(C'_2, E_2) → d_2Angle(F_2, D_2, E_2) → βRotate(A', 72.13°, F_1) → A''Rotate(B', 72.13°, F_1) → B''Rotate(C', 72.13°, F_1) → C''Polygon(A'', B'', C'') → poly1'', c'', a'', b''Rotate(A', 72.13°, F_1) → A''_1Rotate(B', 72.13°, F_1) → B''_1Rotate(C', 72.13°, F_1) → C''_1Polygon(A''_1, B''_1, C''_1) → poly1''_1, c''_1, a''_1, b''_1Rotate(D_2, 72.13°, F_1) → D'Rotate(B'_1, 72.13°, F_1) → ESegment(D', E) → fRotate(A'_1, 72.13°, F_1) → DRotate(F_2, 72.13°, F_1) → F'Segment(D, F') → eRotate(C'_2, 72.13°, F_1) → FRotate(E_2, 72.13°, F_1) → E'Segment(F, E') → dAngle(F, D, E) → γ