四边形的秘密
几何画板及绘图内容加载中,请稍等……
这个范例展示了四边形的一个有趣但不常见的性质。它涉及四边形的角度和旋转等核心几何概念。通过使用GeoGebra中的Polygon, Angle, Rotate, Ray, Intersect等命令,可以动态地探索四边形的性质。适合初中及以上学生或教师使用,帮助理解几何变换和四边形的性质。
GeoGebra 命令及参数
Polygon(A, B, C, D) → poly1, a, b, c, dAngle(B, A, D) → αAngle(A, D, C) → βAngle(D, C, B) → γAngle(C, B, A) → δRotate(B, α / 2, A) → B'Angle(B, A, B') → εRay(A, B') → fRotate(A, β / 2, D) → A'Angle(A, D, A') → ζRay(D, A') → gRotate(D, γ / 2, C) → D'Angle(D, C, D') → ηRay(C, D') → hRotate(C, δ / 2, B) → C'Angle(C, B, C') → θRay(B, C') → iIntersect(h, i) → FIntersect(f, i) → EIntersect(f, g) → HIntersect(g, h) → GCircle(G, F, E) → eLine(E, G) → jLine(H, F) → kMidpoint(D, C) → IMidpoint(B, C) → JMidpoint(A, B) → KMidpoint(A, D) → LLine(D, C) → lLine(C, B) → mLine(B, A) → nLine(A, D) → pIntersect(p, m) → MIntersect(n, l) → NMin({a, b, c, d}) → oCircle(A, (0.25 * o)) → rCircle(B, (0.25 * o)) → qCircle(D, (0.25 * o)) → sCircle(C, (0.25 * o)) → tIntersect(q, m, 1) → OIntersect(q, i, 1) → PIntersect(r, n, 1) → QIntersect(r, f, 1) → RIntersect(s, p, 1) → SIntersect(s, g, 1) → TIntersect(t, l, 1) → UIntersect(t, h, 1) → VCircleSector(A, Q, R) → c_1CircleSector(C, U, V) → d_1CircleSector(B, O, P) → e_1CircleSector(D, S, T) → f_1Dilate(B, If[0 < u ≤ 1, 1 - u, 0], F) → B'_1Dilate(C, If[0 < u ≤ 1, 1 - u, 0], F) → C'_1Segment(B, B'_1) → g_1Segment(C, C'_1) → h_1Dilate(D, If[1 < u ≤ 2, 2 - u, 0], H) → D'_1Segment(D, D'_1) → i_1Dilate(A, If[1 < u ≤ 2, 2 - u, 0], H) → A'_1Segment(A, A'_1) → j_1Rotate(e_1, If[2 < u ≤ 3, ((u - 2) * θ), θ], B) → k_1Rotate(d_1, If[3 < u ≤ 4, ((u - 3) * η), η], C) → p_1Rotate(f_1, If[4 < u ≤ 5, ((u - 4) * ζ), ζ], D) → q_1Rotate(c_1, If[5 < u ≤ 6, ((u - 5) * ε), ε], A) → r_1Center(e) → WRotate(E, If[7.5 < u ≤ 8.5, (((u - 7.5) * 2) * π), (2 * π)], W) → E'CircleArc(W, E, E') → s_1