五边形内角与外角定理的变换几何探究 by Mrs. Cole
几何画板及绘图内容加载中,请稍等……
本范例通过动态几何Applet,利用平移、旋转、镜像等变换工具,直观演示五边形内角和与外角和的定理。核心数学概念包括多边形内角和公式((n-2)×180°)、外角和恒为360°,以及变换几何中的保角性质。作图要点:使用GeoGebra的Segment、Midpoint、Ray、Circle、Intersect等命令构造基本图形,再通过Vector、Translate、Mirror、Dilate、Rotate等变换命令将角或边进行移动、旋转,从而将分散的角集中到一点或一条直线上,便于学生观察角度之和。适合初中几何教学或高中复习,用于帮助学生从变换角度理解多边形角度定理,培养几何直观与推理能力。
GeoGebra 命令及参数
Segment(D, E) → i_3Midpoint(i_3) → M_3Ray(A, B) → aRay(B, C) → bRay(C, D) → cRay(D, E) → dRay(E, A) → eCircle(A, 1.5) → fCircle(B, 1.5) → gCircle(C, 1.5) → hCircle(D, 1.5) → kCircle(E, 1.5) → pSegment(C, A) → iSegment(C, E) → jIntersect(f, a, 1) → FIntersect(f, i, 1) → GIntersect(f, e, 1) → HIntersect(f, e, 2) → IIntersect(p, e) → J,Intersect(p, j) → K,Intersect(p, d, 1) → LIntersect(p, d, 2) → MIntersect(k, d, 1) → NIntersect(k, c, 2) → OIntersect(h, c, 1) → PIntersect(h, j, 1) → QIntersect(h, i, 1) → RIntersect(h, b, 1) → SIntersect(g, a, 2) → TIntersect(g, b, 1) → UIntersect(g, a, 1) → VCircleSector(A, F, G) → qCircleSector(A, G, H) → rCircleSector(B, U, V) → sCircleSector(C, P, Q) → tCircleSector(C, Q, R) → c_1CircleSector(C, R, S) → d_1Intersect(k, c, 1) → WCircleSector(D, O, N) → e_1CircleSector(D, N, W) → f_1CircleSector(E, M, J) → g_1CircleSector(E, J, K) → h_1CircleSector(E, K, L) → k_1CircleSector(A, I, F) → p_1CircleSector(B, T, U) → q_1Intersect(h, b, 2) → ZCircleSector(C, Z, P) → r_1Vector(A, B) → uVector(C, B) → vVector(E, D) → wVector(C, D) → u_1Vector(C, E) → v_1Vector(A, E) → w_1Translate(d_1, v) → s_1Mirror(s_1, B) → t_1Dilate(A, If[0 < l ≤ 1, 1 - l, 0], B) → A'Dilate(C, If[0 < l ≤ 1, 1 - l, 0], B) → C'Dilate(A, If[1 < l ≤ 2, 2 - l, 0], E) → A'_1Dilate(C, If[1 < l ≤ 2, 2 - l, 0], E) → C'_1Dilate(C, If[2 < l ≤ 3, 3 - l, 0], D) → C'_2Vector(A, B) → a_1Vector(C, C') → b_1Vector(A, A'_1) → i_1Rotate(E, If[2 < l ≤ 3, (((-(l - 2)) * 180))°, -180°], M_3) → E'Vector(E, E') → j_1Vector(C, C'_2) → l_1Vector(C, C'_1) → m_1Translate(d_1, b_1) → c_2Translate(r, i_1) → r'_1Translate(r, w_1) → r'_2Translate(k_1, w) → d_2Translate(k_1, j_1) → e_2Translate(c_1, v_1) → f_2Translate(c_1, m_1) → g_2Translate(t, u_1) → t'Translate(t, l_1) → t'_1Translate(q, a_1) → r'Translate(d_1, b_1) → h_2Vector(A, A') → n_1Line(E, C) → a_2Line(E, D) → b_2Segment(E, C) → i_2Vector(D, C) → u_2Vector(E, C) → v_2Vector(A, C) → w_2Vector(B, C) → l_2Dilate(B, If[0 < o < 1, 1 - o, 0], C) → B'Dilate(A, If[1 < o < 2, 2 - o, 0], C) → A'_2Dilate(E, If[2 < o < 3, 3 - o, 0], C) → E'_1Dilate(D, If[3 < o < 4, 4 - o, 0], C) → D'Vector(B, B') → m_2Vector(A, A'_2) → n_2Vector(E, E'_1) → s_2Vector(D, D') → t_2Translate(q_1, m_2) → c_3Translate(q_1, l_2) → d_3Translate(p_1, w_2) → e_3Translate(g_1, v_2) → f_3Translate(e_1, u_2) → g_3If(1 < o < 2, Translate[p_1, n_2]) → h_3If(2 < o < 3, Translate[g_1, s_2]) → k_3If(3 < o < 4, Translate[e_1, t_2]) → p_3Point(a_2) → A_1Point(a_2) → B_1Ray(C, B_1) → a_3Ray(E, A_1) → b_3Polygon(A, B, C, D, E) → poly1, a_4, b_4, c_4, d_4, e_4Polygon(A, B, C) → poly2, c_5, a_5, b_5Polygon(A, C, E) → poly3, e_5, a_6, c_6Polygon(E, C, D) → poly4, d_5, e_6, c_7Segment(E, A) → j_3Segment(A, B) → l_3Segment(B, C) → m_3Segment(C, D) → n_3Midpoint(j_3) → M_4Midpoint(l_3) → M_5Midpoint(m_3) → M_1Midpoint(n_3) → M_2Rotate(d_1, If[0 < l ≤ 1, (((-l) * 180))°, -180°], M_1) → k_2Rotate(C, If[0 < l ≤ 1, (((-l) * 180))°, -180°], M_1) → C'_3Segment(M_1, C'_3) → q_3Rotate(q, If[0 < l ≤ 1, ((l * 180))°, 180°], M_5) → q'Rotate(A, If[0 < l ≤ 1, ((l * 180))°, 180°], M_5) → A'_3Rotate(R, 180°, M_1) → R'Line(B, R') → s_3Segment(M_5, A'_3) → r_3Rotate(r, If[1 < l ≤ 2, (((-(l - 1)) * 180))°, -180°], M_4) → r'_3Rotate(A, If[1 < l ≤ 2, (((-(l - 1)) * 180))°, -180°], M_4) → A'_4Segment(M_4, A'_4) → p_2Rotate(t, If[2 < l ≤ 3, (((l - 2) * 180))°, 180°], M_2) → t'_2Rotate(C, If[2 < l ≤ 3, (((l - 2) * 180))°, 180°], M_2) → C'_4Segment(M_2, C'_4) → q_2Vector(E, D) → j_2Translate(L, j_2) → L'Ray(D, L') → r_2CircleArc(C, R, S) → t_3CircleArc(C, Q, R) → f_4CircleArc(C, P, Q) → g_4CircleArc(A, F, G) → h_4CircleArc(A, G, H) → k_4CircleArc(E, K, L) → p_4Segment(M_3, E') → i_4
AI 绘图提示语参考
绘制一个五边形ABCDE,并使用变换几何工具展示其内角和外角的性质。首先画出五边形的边,然后以每个顶点为中心画圆,接着通过交点找到内角和外角的位置,最后利用平移、旋转和反射等变换将所有内角或外角集中到一个顶点或一条线上,直观展示内角和为540度,外角和为360度。
以上提示语为根据原始绘图命令整理而来,仅供参考。