正方形金字塔展开图:动画演示几何拼合
几何画板及绘图内容加载中,请稍等……
该范例通过动画演示“正方形金字塔”的展开图如何由若干三角形与边界对应关系拼合成立体。核心概念包括立体几何中的曲面展开、正方锥侧面为等腰三角形、网格(net)与对应边的同长与夹角保持、以及利用中点、角平分线与圆弧进行几何构造。作图要点:从“构造摘要”可见其使用了 Point、Segment、Line、Circle、Intersect 来确定关键点、边界线与交点;借助 Rotate 与 Translate 完成侧面三角形的对称与重复摆放以形成展开网;用 Polygon 生成多边形轮廓;通过 Midpoint、OrthogonalLine(正交线)、Angle(角)与 LineBisector(角平分线)建立几何约束;利用 CircleArc 与 Ray 确定圆弧与射线辅助角度/长度对应。对象如 A,s,B 等用于标定顶点与边界,poly1、d/e/f 等用于构造展开面各三角块。适合中学到高中几何教学,尤其用于立体几何入门、几何展开与拼合推理、以及课堂演示与课后探究。
GeoGebra 命令及参数
Point(Circle[A, s]) → BSegment(A, B) → aLine(A, B) → b_2Circle(B, (3 * s / 4.5)) → cIntersect(c, b_2, 2) → CRotate(C, 30°, B) → C'Line(C', b_2) → dSegment(B, C') → eLine(A, e) → fIntersect(d, f) → DPolygon(A, B, C', D) → poly1, a_1, b_1, c', d_1Segment(A, C') → gSegment(D, B) → h_1Intersect(g, h_1) → EOrthogonalLine(E, a_1) → iCircle(E, h) → kIntersect(k, i, 2) → FSegment(B, F) → jSegment(C', F) → l_5Segment(F, D) → mSegment(F, A) → nSegment(E, F) → pSegment(A, D) → qMidpoint(b_1) → GSegment(G, F) → rAngle(G, E, F) → αSegment(E, G) → tLine(E, G) → c_1Circle(G, F) → f_1Intersect(f_1, c_1, 2) → HIntersect(c_1, d_1) → ICircle(I, F) → g_1Intersect(g_1, c_1, 1) → JVector(F, J) → uPoint(c') → LCircle(L, F) → q_1Vector(F, H) → wMidpoint(A, B) → KLine(K, E) → e_1Circle(K, h) → p_1Intersect(e_1, c') → MCircle(M, h) → r_1Intersect(r_1, e_1, 2) → NIntersect(p_1, e_1, 1) → OVector(F, N) → vVector(F, O) → zTranslate(F, Vector[(z * o)]) → F'_1Translate(F, Vector[(u * (o - 1))]) → F'_2Translate(F, Vector[(v * (o - 2))]) → F'_3Translate(F, Vector[(w * (o - 3))]) → F'Segment(F, N) → s_{4}LineBisector(s_{4}) → a_2Intersect(a_2, c') → PCircleArc(P, N, F) → c_2Ray(P, F'_3) → d_2Intersect(c_2, d_2, 1) → QSegment(F, O) → e_2LineBisector(e_2) → f_2Intersect(f_2, a_1) → RCircleArc(R, F, O) → g_2Ray(R, F'_1) → h_2Intersect(g_2, h_2, 1) → SCircleArc(I, F, J) → k_2CircleArc(G, H, F) → p_2Ray(I, F'_2) → i_2Intersect(k_2, i_2, 1) → TRay(G, F') → j_2Intersect(p_2, j_2, 1) → UCircle(I, E) → s_1OrthogonalLine(I, a_1) → i_1Intersect(s_1, i_1, 2) → VIntersect(s_1, i_1, 1) → WOrthogonalLine(V, i_1) → j_1OrthogonalLine(W, i_1) → k_1OrthogonalLine(G, k_1) → l_1Intersect(j_1, l_1) → ZIntersect(k_1, l_1) → A_1Midpoint(V, Z) → B_1Midpoint(A_1, W) → C_1Circle(B_1, r) → t_1Circle(C_1, r) → q_2OrthogonalLine(B_1, k_1) → m_1Intersect(t_1, m_1, 1) → D_1Intersect(q_2, m_1, 2) → E_1Vector(C', Z) → u_1Vector(B, A_1) → v_1Vector(N, D_1) → w_1Vector(O, E_1) → z_1Translate(N, Vector[(w_1 * (o - 4))]) → N'Translate(O, Vector[(z_1 * (o - 4))]) → O'Translate(B, Vector[(v_1 * (o - 4))]) → B'Translate(A, Vector[(v_1 * (o - 4))]) → A'Translate(C', Vector[(u_1 * (o - 4))]) → C''Translate(D, Vector[(u_1 * (o - 4))]) → D'If(o < 1, S, If[o < 4, O, If[o < 5, O', E_1]]) → F_1If(o < 1, F, If[o < 2, T, J]) → G_1If(o < 3, F, If[o < 4, U, H]) → H_1If(o < 2, F, If[o < 3, Q, If[o < 4, N, If[o < 5, N', D_1]]]) → I_1If(o < 4, A, If[o < 5, A', W]) → J_1If(o < 4, B, If[o < 5, B', A_1]) → K_1If(o < 4, C', If[o < 5, C'', Z]) → L_1If(o < 4, D, If[o < 5, D', V]) → M_1Polygon(F_1, J_1, K_1) → poly2, k_3, f_3, j_3Polygon(L_1, H_1, K_1) → poly3, k_4, l_2, h_3Polygon(L_1, I_1, M_1) → poly4, m_2, l_3, i_3Polygon(M_1, G_1, J_1) → poly5, j_4, m_3, g_3Intersect(m, j_3) → N_1Segment(I_1, N_1) → n_1Intersect(j_3, i_3) → O_1Intersect(c', i_3) → Q_1Intersect(c', i_3) → R_1Intersect(c', i_3) → S_1Intersect(c', i_3) → U_1Intersect(c', i_3) → A_2Intersect(l_2, i_3) → B_2Segment(B_2, O_1) → n_2Segment(B_2, M_1) → r_2Midpoint(M_1, L_1) → C_2Midpoint(L_1, K_1) → D_2Midpoint(K_1, J_1) → E_2Midpoint(J_1, M_1) → F_2Segment(G_1, F_2) → s_2Segment(C_2, I_1) → t_2Segment(D_2, H_1) → a_3Segment(E_2, F_1) → b_3Polygon(J_1, M_1, L_1, K_1) → poly6, j_5, m_4, l_4, k_5Intersect(j_3, d_1) → P_1Segment(P_1, M_1) → c_3Midpoint(p) → V_1OrthogonalLine(V_1, p) → d_3Point(d_3) → W_1Vector(W_1, V_1) → u_2Midpoint(r) → T_1Midpoint(a_3) → Z_1Point(a_2) → G_2Vector(G_2, T_1) → v_2Vector(G_2, Z_1) → w_2Point(Circle[H_2, s]) → I_2Segment(H_2, I_2) → e_3Line(H_2, I_2) → bCircle(I_2, (3 * s / 4.5)) → p_3Intersect(p_3, b, 2) → J_2Rotate(J_2, 30°, I_2) → K_2Segment(I_2, K_2) → n_3Line(K_2, b) → q_3Line(H_2, n_3) → r_3Intersect(q_3, r_3) → L_2Segment(H_2, K_2) → s_3Segment(I_2, L_2) → t_3Intersect(s_3, t_3) → M_2Circle(M_2, h) → c_4OrthogonalLine(M_2, b) → a_4Intersect(c_4, a_4, 2) → N_2Polygon(H_2, N_2, I_2) → poly7, i_4, h_4, n_4Polygon(I_2, N_2, K_2) → poly8, k_6, i_5, n_5Polygon(H_2, L_2, K_2, I_2) → poly9, h_5, l_6, k_7, i_6Polygon(H_2, N_2, L_2) → poly10, l_7, h_6, n_6Polygon(L_2, N_2, K_2) → poly11, k_8, l_8, n_7Midpoint(k_7) → O_2Segment(M_2, O_2) → b_4Segment(M_2, N_2) → d_4Segment(N_2, O_2) → e_4Angle(O_2, M_2, N_2) → βMidpoint(N_2, M_2) → P_2Midpoint(O_2, N_2) → Q_2Line(P_2, Q_2) → f_4Circle(P_2, s) → g_4Intersect(g_4, f_4, 1) → R_2Intersect(g_4, f_4, 2) → S_2Vector(R_2, P_2) → z_2Vector(S_2, Q_2) → u_3Midpoint(b_3) → V_2
AI 绘图提示语参考
绘制一个正方形金字塔的表面展开图,首先创建一个正方形底面和四个等腰三角形侧面。通过旋转和移动三角形,将它们围绕底面排列,形成展开图。注意保持边长和角度不变,确保展开图的正确性。
以上提示语为根据原始绘图命令整理而来,仅供参考。