三角形高线与外接圆动态关系
几何画板及绘图内容加载中,请稍等……
①本范例演示了三角形两条高线、外接圆以及从第三顶点引出的切线之间的动态可变关系;②涉及核心数学概念包括外接圆、乘积、除法、高线、切线、旋转、向量等;③作图要点提炼自GeoGebra命令:Rotate(旋转)、Ray(射线)、Point(点)、Segment(线段)、Line(直线)、OrthogonalLine(垂线)、Intersect(交点)、Min(最小值)、Circle(圆)、Angle(角度)、LineBisector(角平分线)、CircleArc(圆弧)、Dilate(缩放)、CircleSector(扇形)、Vector(向量)、Translate(平移)、Polygon(多边形);④适合高中及以上数学学习者探索几何关系与动态几何软件应用。
GeoGebra 命令及参数
Rotate(B, (a * π / 180), A) → B'Ray(A, B') → gPoint(g) → CSegment(A, C) → q_1Line(C, B) → rLine(A, C) → qOrthogonalLine(B, q) → f_1Intersect(q, f_1) → HSegment(C, H) → r_1Min(q_1, r_1) → vCircle(C, (0.4 * v)) → s_1Intersect(s_1, r) → O, PIntersect(s_1, q) → M, NAngle(M, C, P) → ζSegment(C, B) → jLineBisector(j) → kSegment(A, C) → iLineBisector(i) → lIntersect(k, l) → DLine(D, C) → mOrthogonalLine(C, m) → nIntersect(s_1, n) → Q, RAngle(A, C, Q) → κAngle(B, A, B') → αRay(A, B) → fSegment(A, B) → hRotate(C, If[0 < b ≤ 2, ((b - 2) * π), (2 * π)], D) → C'CircleArc(D, C, C') → cCircle(D, C) → dCircle(C, 3) → eIntersect(e, n, 1) → EIntersect(e, n, 2) → FAngle(D, C, E) → βDilate(D, If[2 < b ≤ 3, 3 - b, 0], C) → D'Segment(D, D') → pOrthogonalLine(A, r) → sIntersect(r, s) → GAngle(A, G, B) → γDilate(A, If[3 < b ≤ 4, 4 - b, 0], G) → A'Segment(A, A') → tDilate(B, If[4 < b ≤ 5, 5 - b, 0], H) → B'_1Segment(B, B'_1) → g_1Angle(A, H, B) → δDilate(H, If[5 < b ≤ 6, 6 - b, 0], G) → H'Segment(H, H') → h_1Line(H, G) → i_1Segment(H, C) → j_1Segment(H, A) → k_1Intersect(d, i_1) → I, JSegment(H, G) → l_1Segment(H, I) → m_1Min({j_1, k_1, l_1, m_1}) → oCircle(H, (0.4 * o)) → c_1Intersect(c_1, q, 1) → KIntersect(c_1, i_1, 2) → LAngle(K, H, L) → εRotate(K, If[7 < b ≤ 8, ((b - 7) * ε), ε], H) → K'CircleSector(H, K, K') → d_1Dilate(H, If[8.5 < b ≤ 9.5, 9.5 - b, 0], C) → H'_1Vector(H, H'_1) → uTranslate(d_1, u) → e_1Polygon(A, B, C) → poly1, c_2, a_1, b_1Segment(A, B) → n_1Segment(A, H) → p_1Rotate(M, If[7 < b ≤ 8, ((b - 7) * κ), κ], C) → M'CircleSector(C, M, M') → t_1Dilate(C, If[8.5 < b ≤ 9.5, 9.5 - b, 0], H) → C'_1Vector(C, C'_1) → wTranslate(t_1, w) → d_2Dilate(D, If[-1 < b < 0, (-b), 0], C) → D'_1Segment(D, D'_1) → f_2Rotate(D, If[0 < b ≤ 2, ((b - 2) * π), (2 * π)], D) → D'_2Rotate(D'_1, If[0 < b ≤ 2, ((b - 2) * π), (2 * π)], D) → TSegment(D'_2, T) → g_2Segment(C, A) → h_2Min(h_2, n_1) → o_1Circle(A, (0.15 * o_1)) → e_2Intersect(e_2, n_1) → U,Intersect(e_2, h_2) → V,CircleSector(A, U, V) → k_2