棱柱展开与折叠网图探索
几何画板及绘图内容加载中,请稍等……
该范例演示如何为棱柱“展开成平面网图”,再将网图折叠回立体,并通过改变棱柱尺寸观察其几何结构变化。核心数学概念包括棱柱的面与棱的对应关系、平面展开(net)的组成、长方体/矩形棱柱与一般棱柱的网图规律,以及用几何约束保持边长与相邻面连接。作图要点:利用 GeoGebra 的 Point、Segment、Polygon、Rotate、Intersect 等命令生成并定位各个面与边;用 Prism、Net、Surface 构建/标识棱柱及其展开网;通过 Circle、Ray、Sequence 与 OrthogonalLine 辅助定义几何参考与可视化结构;借助 Cartesian 坐标系组织图元;同时用 Cylinder、Cone 等对象用于拓展同类立体(如圆柱、圆锥)的网图与对比。适合中学 6–8 年级进行立体几何入门与“找展开图”技能训练,也可用于课堂探究活动或几何作图练习。
GeoGebra 命令及参数
Point(yAxis) → CAPoint(yAxis) → CBCircle(CA, CB) → cCilPoint(cCil) → CRay(A, (x(A), y(A), 40)) → hPoint(yAxis) → BSequence(Rotate[C, ((t * 2) * pi / n), A], t, 1, n) → vertPolygon(vert) → polyOrthogonalLine(C, xOyPlane) → fSegment(HC, (x(C), y(C), 4)) → gPoint(g) → EPrism(poly, Segment[C, E]) → a, F, face3, face4, face5, face6, face2, face13, face15, faceFGHIJK, edge1, edge2, G, edge3, edge4, edge5, edge6, edge13, edge16, edgeFG, edgeGH, edgeHI, edgeIJ, H, edgeJK, edgeFK, edge14, edge17, I, J, K, L, M, face1Point(Segment[(0, 0, 0.1), (0, 0, 4)]) → CDPyramid(poly, CD) → b, face7, edge8, edge9, edge10, edge11, edge12, edge15, edge18, face9, face10, face11, face12, face8, face14, face16, edge7Net(a, (-open)) → prismNet, N, W, Z, A_1, B_1, C_1, D_1, E_1, F_1, G_1, H_1, O, I_1, J_1, K_1, L_1, M_1, N_1, O_1, P_1, Q_1, R_1, P, S_1, face17, face18, face19, face20, face21, face22, face23, face24, face34, Q, face35, edge19, edge20, edge21, edge22, edge23, edge24, edge25, edge26, edge27, R, edge28, edge29, edge30, edge31, edge32, edge33, edge34, edge35, edge36, edge37, S, edge38, edge39, edge40, edge41, edge42, edge43, edge44, edge45, edge70, edge71, T, edge72, edge73, edge74, edge75, edge76, edge77, edge78, edge79, edge80, edge81, U, VNet(b, (-open)) → pyrNet, T_1, E_2, F_2, G_2, H_2, I_2, J_2, K_2, face25, face26, face27, U_1, face28, face29, face30, face31, face32, face33, edge46, edge47, edge48, edge49, V_1, edge50, edge51, edge52, edge53, edge54, edge55, edge56, edge57, edge58, edge59, W_1, edge60, edge61, edge62, edge63, edge64, edge65, edge66, edge67, edge68, edge69, Z_1, A_2, B_2, C_2, D_2Random(3, 8) → nRandCircle(CA, CB) → dCylinder(cCil, 3) → bCil, eCil, fCilLine(CC, xAxis) → aCilOrthogonalLine(CD, xOyPlane) → gCilCircle(gCil, CC) → kCilRotate(Rotate[eCil, ϕCil, aCil], ϕCil, xAxis) → eeCilRotate(Rotate[eCil, ϕCil, aCil], ϕCil, xAxis) → dCilCircle(CA, CB) → hCilIf(abs(tCil) < 1, ((rCil * sin((-θCil))), ((rCil * (1 - cos((-θCil)))) * cos(ϕCil)) - (3 * sin(ϕCil)), (3 * cos(ϕCil)) + ((rCil * (1 - cos((-θCil)))) * sin(ϕCil))), ((-pi), (-3 * sin(ϕCil)), (3 * cos(ϕCil)))) → CEIf(abs(tCil) < 1, ((rCil * sin(θCil)), ((rCil * (1 - cos(θCil))) * cos(ϕCil)) - (3 * sin(ϕCil)), (3 * cos(ϕCil)) + ((rCil * (1 - cos(θCil))) * sin(ϕCil))), (pi, (-3 * sin(ϕCil)), (3 * cos(ϕCil)))) → CFIf(abs(tCil) < 1, ((rCil * sin((-θCil))), ((rCil * (1 - cos((-θCil)))) * cos(ϕCil)), ((rCil * (1 - cos((-θCil)))) * sin(ϕCil))), ((-pi), 0, 0)) → CGIf(abs(tCil) < 1, ((rCil * sin(θCil)), ((rCil * (1 - cos(θCil))) * cos(ϕCil)), ((rCil * (1 - cos(θCil))) * sin(ϕCil))), (pi, 0, 0)) → CHSegment(CE, CG) → mCilSegment(CF, CH) → nCilLine((0, 1, 0), zAxis) → pCilCircle(pCil, CB) → qCilCircle(pCil, CB) → sCilOrthogonalLine((1, 0, 0), xOyPlane) → aConCircle(aCon, (0, 0, 0)) → cConPoint(aCon) → KAIntersect(xAxis, aCon) → KBCone(KB, KA, 1) → bCon, dCon, eConIntersect(yAxis, xAxis) → KCSegment(KC, KA) → lConDistance(KB, KC) → rConAngle(KA, KC, KB) → αRotate(KA, (abs(tCil) * α), yAxis) → KAAOrthogonalLine(KAA, xOyPlane) → fConIntersect(fCon, xOyPlane) → KBBRotate(KC, bet / 2, fCon) → KCCRotate(KC, ((-bet)) / 2, fCon) → KCRCircumcircleArc(KCC, KC, KCR) → gConDistance(KAA, KBB) → hConDistance(KBB, KCC) → rcConSurface(((kCon - ((v * rcCon) * cos((u * bet / 2)))) * cos(ϕCon)) - (((1 - v) * hCon) * sin(ϕCon)), ((v * rcCon) * sin((u * bet / 2))), (((1 - v) * hCon) * cos(ϕCon)) + ((kCon - ((v * rcCon) * cos((u * bet / 2)))) * sin(ϕCon)), u, -1, 1, v, 0, 1) → jConCurveCartesian(((kCon - (rcCon * cos((u * bet / 2)))) * cos(ϕCon)), (rcCon * sin((u * bet / 2))), ((kCon - (rcCon * cos((u * bet / 2)))) * sin(ϕCon)), u, -1, 1) → mConSegment(KE, KF) → nConSegment(KD, KF) → pConIf(abs(tCil) < 1, CurveCartesian[(rCil * sin((u * θCil))), ((rCil * (1 - cos((u * θCil)))) * cos(ϕCil)) - (3 * sin(ϕCil)), (3 * cos(ϕCil)) + ((rCil * (1 - cos((u * θCil)))) * sin(ϕCil)), u, -1, 1], CurveCartesian[(pi * u), (-3 * sin(ϕCil)), (3 * cos(ϕCil)), u, -1, 1]) → jCilIf(abs(tCil) < 1, CurveCartesian[(rCil * sin((u * θCil))), ((rCil * (1 - cos((u * θCil)))) * cos(ϕCil)), ((rCil * (1 - cos((u * θCil)))) * sin(ϕCil)), u, -1, 1], CurveCartesian[(pi * u), 0, 0, u, -1, 1]) → lCilIf(abs(tCil) < 1, Surface[(rCil * sin((u * θCil))), ((rCil * (1 - cos((u * θCil)))) * cos(ϕCil)) - (v * sin(ϕCil)), (v * cos(ϕCil)) + ((rCil * (1 - cos((u * θCil)))) * sin(ϕCil)), u, -1, 1, v, 0, 3], Surface[(pi * u), ((-v) * sin(ϕCil)), (v * cos(ϕCil)), u, -1, 1, v, 0, 3]) → iCilSegment(R_1, V) → missingSide
AI 绘图提示语参考
画一个可折叠的棱柱几何图:先在空间中给定一圆以确定底面边界,再以底面多边形为核心构造棱柱的侧面与底面;同时放置一条参考平面并生成棱柱的三维实体可视化。随后把棱柱沿相邻面关系展开成二维网格:各个面以多边形块表示,并在展开图中保留对应的公共边,用旋转与连接使相邻面正确贴合。再展示等价的金字塔网作为对比,并保留可调的棱柱参数,使学生能观察底边尺寸变化后网与实体如何同步调整。
以上提示语为根据原始绘图命令整理而来,仅供参考。