旗帜周长与面积动态演示
几何画板及绘图内容加载中,请稍等……
① 该范例演示如何通过几何作图构造一面旗帜形状,并实时计算其周长与面积。② 涉及核心数学概念包括周长、面积、微积分求积分、二维向量、交点求解、二次方程及缩放变换。③ 作图要点:使用 Segment、Point、Circle、Intersect、OrthogonalLine、Polygon、PointIn 等命令,配合大量点对象(A、B、C、D、E、F、G、H、I、J、K、L、M、N、O、P、Q、R、S、T、U、V、W、Z、A_1、B_1、C_1、D_1 等)构建旗帜轮廓并标记内部区域。④ 适合高中几何、微积分及向量教学,也可作为大学几何建模与动态演示的教学素材。
GeoGebra 命令及参数
Segment(A, B) → aSegment(A, C) → bSegment(C, D) → cSegment(D, B) → dPoint(b) → ECircle(E, e / 2) → fPoint(d) → FCircle(F, e / 2) → gPoint(a) → GCircle(G, e / 2) → hPoint(c) → HCircle(H, e / 2) → kIntersect(f, b) → I, JIntersect(h, a) → K, LIntersect(d, xAxis) → MIntersect(d, xAxis) → NIntersect(d, xAxis) → OIntersect(d, xAxis) → PIntersect(d, xAxis) → QIntersect(d, xAxis) → RIntersect(d, xAxis) → SIntersect(k, c) → T, UIntersect(d, xAxis) → VIntersect(d, xAxis) → WIntersect(d, xAxis) → ZIntersect(d, xAxis) → A_1Segment(B, D) → iIntersect(d, i) → B_1Intersect(d, i) → C_1Intersect(d, i) → D_1OrthogonalLine(I, b) → jOrthogonalLine(J, b) → lIntersect(j, d) → E_1Intersect(l, d) → F_1Segment(I, E_1) → mSegment(J, F_1) → nIntersect(b, n) → G_1Segment(K, T) → pSegment(U, L) → qIntersect(p, m) → H_1Intersect(q, m) → I_1Intersect(p, n) → J_1Intersect(q, n) → K_1Intersect(a, p) → L_1Polygon(I, H_1, J_1, G_1, L_1, L, I_1, E_1, F_1, K_1, U, T) → poly1, i_1, t, j_1, g_1, h_1, l_1, l_2, i_2, e_1, f_1, k_1, uPointIn(poly1) → Pointpoly1Segment(I, G_1) → rSegment(L_1, H_1) → a_1Segment(I, H_1) → b_1Segment(L_1, L) → c_1Intersect(a_1, b_1) → N_1Segment(L_1, N_1) → q_1Segment(L, I_1) → r_1Segment(I_1, E_1) → s_1Segment(K_1, U) → t_1Segment(G_1, J_1) → a_2Segment(I, N_1) → b_2Segment(K_1, F_1) → c_2Segment(J_1, T) → d_2