等边三角形与矩形面积问题动态演示
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①本范例演示等边三角形内接于矩形的动态图形与面积计算问题;②涉及核心数学概念包括面积计算、解析几何、几何变换;③构造过程中运用了Line(线)、Segment(线段)、Circle(圆)、Intersect(交点)、Rotate(旋转)、Polygon(多边形)等GeoGebra命令与对象;④适合高中数学教学与几何作图学习,可用于理解特殊图形的面积关系与变换性质。
GeoGebra 命令及参数
Line(A, B) → iSegment(A, B) → lOrthogonalLine(B, i) → fCircle(B, l / 2) → dIntersect(d, f, 2) → COrthogonalLine(A, l) → qCircle(B, 1) → cIntersect(c, f, 2) → DRay(B, D) → gRotate(B, α, A) → B'Angle(B, A, B') → βRay(A, B') → hIntersect(g, h) → EPolygon(A, E, 3) → poly1, m, n, p, FPolygon(E, B, A) → poly3, a_1, e, bOrthogonalLine(F, q) → rIntersect(q, r) → GIntersect(r, g) → HPolygon(A, F, G) → poly2, g_1, a, f_1Polygon(E, H, F) → poly4, f_2, e_1, h_1Dilate(A, If[0 < o ≤ 1, 1 - o, 0], E) → A'Segment(A, A') → sDilate(E, If[1 < o ≤ 2, 2 - o, 0], F) → E'Rotate(A, If[1 < o ≤ 2, ((o - 1) * π / 3), π / 3], A) → A'_1Rotate(A', If[1 < o ≤ 2, ((o - 1) * π / 3), π / 3], A) → A''Segment(A'_1, A'') → s'Rotate(A'_1, If[2 < o ≤ 3, ((o - 2) * π / 3), π / 3], F) → IRotate(A'', If[2 < o ≤ 3, ((o - 2) * π / 3), π / 3], F) → A'''Segment(I, A''') → s''Angle(A, G, H) → γAngle(G, H, B) → δAngle(H, B, A) → εSegment(G, F) → tSegment(G, A) → i_1Segment(F, H) → j_1Segment(H, B) → k_1Segment(B, A) → l_1Circle(A, (0.2 * l_1)) → c_1Intersect(c_1, l_1) → J,Intersect(c_1, s) → K,CircleSector(A, J, K) → d_1Segment(B, E) → m_1Segment(B, A) → n_1Segment(H, E) → p_1OrthogonalLine(G, s') → r_1OrthogonalLine(B, s) → s_1Intersect(r_1, s') → LOrthogonalLine(H, s'') → q_1Intersect(q_1, s'') → MIntersect(s_1, s) → NDilate(G, If[4 < o ≤ 5, 5 - o, 0], L) → G'Segment(G, L) → t_1Circle(H, t_1) → c_2Segment(H, M) → b_1Intersect(c_2, b_1) → O, USegment(G, G') → g_2Dilate(B, If[5 < o ≤ 6, 6 - o, 0], N) → B'_1Segment(B, B'_1) → h_2Dilate(H, If[6 < o ≤ 7, 7 - o, 0], O) → H'Segment(H, H') → i_2Dilate(O, If[7 < o ≤ 8, 8 - o, 0], M) → O'Segment(O, O') → j_2Line(O, g_2) → k_2Point(k_2) → PAngle(H, O, P) → ζDilate(L, If[8 < o ≤ 9, 9 - o, 0], O) → L'Vector(L, L') → uTranslate(G, u) → G'_1Translate(G', u) → G''Segment(G'_1, G'') → l_2Rotate(G'_1, If[9 < o ≤ 10, (((-(o - 9)) * 2) * π / 3), (-2 * π / 3)], O) → QRotate(G'', If[9 < o ≤ 10, (((-(o - 9)) * 2) * π / 3), (-2 * π / 3)], O) → G'''Segment(Q, G''') → m_2Line(M, h_2) → n_2Point(n_2) → RAngle(H, M, R) → ηDilate(N, If[10 < o ≤ 11, 11 - o, 0], M) → N'Vector(N, N') → vTranslate(B, v) → B'_2Dilate(B, If[10 < o ≤ 11, 11 - o, 0], M) → B'_3Vector(B, B'_3) → wTranslate(B, w) → B'_4Translate(B'_1, w) → SSegment(B'_4, S) → p_2Rotate(B'_4, If[11 < o ≤ 12, ((-(o - 11)) * π / 3), ((-π)) / 3], M) → TRotate(S, If[11 < o ≤ 12, ((-(o - 11)) * π / 3), ((-π)) / 3], M) → S'Segment(T, S') → q_2Angle(G, L, A) → θAngle(A, N, B) → ιAngle(H, M, A'') → κ