角平分线替代构造法
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①本范例演示了使用替代的尺规方法构造角平分线;②涉及核心数学概念:角、几何作图、尺规工具应用;③作图要点:运用了Intersect(交点)、Ray(射线)、Rotate(旋转)、Angle(角度)、Circle(圆)、CircleSector(圆扇形)、Segment(线段)、Point(点)、CircleArc(圆弧)、Dilate(缩放)等GeoGebra命令/对象;④适合高中数学教学或几何作图爱好者学习。
GeoGebra 命令及参数
Intersect(xAxis, yAxis) → ARay(A, B) → fRotate(B, α, A) → B'Angle(B, A, B') → βRay(A, B') → gCircle(A, 1) → cRotate(B, α / 2, A) → B'_1Angle(B, A, B'_1) → γRay(A, B'_1) → hIntersect(c, h, 1) → CIntersect(c, f, 1) → DCircleSector(A, D, C) → dIntersect(c, g, 1) → ECircleSector(A, D, E) → eCircle(A, a) → kCircle(A, b) → pIntersect(k, f, 1) → FIntersect(k, g, 1) → GIntersect(p, f, 1) → HIntersect(p, g, 1) → ISegment(F, I) → iSegment(H, G) → jIntersect(h, i) → JPoint(h) → KRay(J, K) → lCircleSector(A, H, I) → qRotate(F, If[0 < m ≤ 1, (m * α), α], A) → F'CircleArc(A, F, F') → rRotate(H, If[1 < m ≤ 2, ((m - 1) * α), α], A) → H'CircleArc(A, H, H') → sDilate(F, If[2 < m ≤ 3, 3 - m, 0], I) → F'_1Segment(F, F'_1) → nDilate(H, If[3 < m ≤ 4, 4 - m, 0], G) → H'_1Segment(H, H'_1) → tDilate(A, If[5 < m ≤ 6, 6 - m, 0], J) → A'Segment(A, A') → f_1Rotate(d, If[7 < m ≤ 8, ((m - 7) * α / 2), α / 2], A) → d'