三角形、平行四边形、梯形和菱形的面积
几何画板及绘图内容加载中,请稍等……
本范例演示如何计算特定多边形的面积。通过移动滑块,可以看到这些形状如何“转变”为其他形状。涉及的核心数学概念包括相似变换、面积计算等。使用了Polygon, Midpoint, Segment, OrthogonalLine, Intersect, Rotate, Vector, Line, Point, Angle, Translate, Mirror等GeoGebra命令。适合初中及以上学生学习几何变换和面积计算。
GeoGebra 命令及参数
Polygon(A, B, C) → poly1, c, a, bMidpoint(B, A) → DMidpoint(A, C) → ESegment(D, E) → dOrthogonalLine(A, d) → eIntersect(e, d) → FPolygon(A, F, D) → poly2, d_1, a_1, fPolygon(F, E, A) → poly3, a_2, f_1, e_1Rotate(A, Move, D) → A'Rotate(F, Move, D) → F'Rotate(D, Move, D) → D'Polygon(A', F', D') → poly2', d', a', f'Rotate(F, (-Move), E) → F'_1Rotate(E, (-Move), E) → E'Rotate(A, (-Move), E) → A'_1Polygon(F'_1, E', A'_1) → poly3', a'_1, f'_1, e'OrthogonalLine(A, a) → gIntersect(a, g) → GMidpoint(A, G) → HVector(H, A) → uVector(H, G) → vLine(A, a) → hOrthogonalLine(B, h) → iOrthogonalLine(C, h) → jIntersect(h, i) → IIntersect(h, j) → JPolygon(I, J, C, B) → poly5, i_1, j_1, c_2, b_2Point(i) → KOrthogonalLine(K, j) → kIntersect(j, k) → LMidpoint(K, L) → MVector(M, K) → wVector(M, L) → lAngle(B, A, C) → αAngle(A, C, B) → βAngle(C, B, A) → γLine(C, B) → pOrthogonalLine(A, p) → qLine(C, q) → rLine(A, p) → tIntersect(p, q) → NIntersect(r, t) → OLine(B, r) → g_1Midpoint(A, C) → PIntersect(g_1, b) → QLine(P, a) → h_1Intersect(c, h_1) → RSegment(R, P) → k_1Segment(Q, B) → l_1Intersect(k_1, l_1) → SSegment(S, B) → m_1Polygon(A, R, P) → poly7, p_1, a_4, r_1Polygon(R, B, S) → poly8, s_1, r_2, b_3Intersect(m_1, s_1) → TPolygon(S, T, C, P) → poly9, s_2, t_1, c_4, p_2Rotate(A, (-Move), P) → A'_2Rotate(R, (-Move), P) → R'Rotate(P, (-Move), P) → P'Polygon(A'_2, R', P') → poly7', p', a'_2, r'Vector(T, C) → u_1Translate(R, Vector[(Move / π * u_1)]) → R'_1Translate(B, Vector[(Move / π * u_1)]) → B'Translate(S, Vector[(Move / π * u_1)]) → S'Polygon(R'_1, B', S') → poly8', s', r'_1, b'OrthogonalLine(T, t) → n_1Intersect(t, n_1) → UPolygon(U, O, C, T) → poly6, u_2, o_1, c_3, t_2OrthogonalLine(B, q) → q_1Intersect(q, q_1) → VMidpoint(A, V) → WVector(W, A) → v_1Vector(W, V) → w_1Midpoint(B, A) → ZSegment(E, Z) → nOrthogonalLine(C, n) → f_2Intersect(f_2, n) → A_1Segment(A_1, C) → g_2Polygon(B, Z, A_1, C) → poly10, b_4, z_1, a_3, c_5Polygon(Z, E, A) → poly11, a_5, z_2, e_3Polygon(E, C, A_1) → poly12, a_6, e_4, c_6Rotate(Z, Move, Z) → Z'Rotate(E, Move, Z) → E'_1Rotate(A, Move, Z) → A'_3Polygon(Z', E'_1, A'_3) → poly11', a'_3, z', e'_1Translate(E, Vector[(Move / π * (w - l))]) → E'_2Translate(C, Vector[(Move / π * (w - l))]) → C'Translate(A_1, Vector[(Move / π * (w - l))]) → B_1Polygon(E'_2, C', B_1) → poly12', b_5, e'_2, c'OrthogonalLine(B, n) → b_1Intersect(b_1, n) → C_1Polygon(B, C_1, E, C) → poly4, c_1, d_2, e_2, h_2Polygon(Z, B, C, E) → poly13, i_2, j_2, k_2, l_2Segment(D_1, E_1) → m_2Segment(D_1, F_1) → n_2Line(F_1, m_2) → q_2Line(E_1, n_2) → d_3Intersect(q_2, d_3) → G_1Segment(E_1, G_1) → f_3Segment(G_1, F_1) → g_3OrthogonalLine(D_1, g_3) → h_3Intersect(h_3, g_3) → H_1Polygon(D_1, H_1, F_1) → poly14, f_4, d_4, h_4Polygon(H_1, G_1, E_1, D_1) → poly15, h_5, g_4, e_5, d_5Polygon(D_1, F_1, G_1, E_1) → poly16, d_6, f_5, g_5, e_6Vector(F_1, G_1) → v_2Translate(D_1, Vector[(Move / π * v_2)]) → I_1Translate(H_1, Vector[(Move / π * v_2)]) → J_1Translate(F_1, Vector[(Move / π * v_2)]) → K_1Polygon(I_1, J_1, K_1) → poly14', k_3, i_3, j_3Angle(G_1, F_1, D_1) → δAngle(E_1, G_1, F_1) → εOrthogonalLine(E_1, q_2) → l_3Intersect(q_2, l_3) → L_1Polygon(D_1, H_1, L_1, E_1) → poly17, d_7, h_6, l_4, e_7OrthogonalLine(F_1, e_5) → m_3Intersect(m_3, e_5) → M_1Polygon(M_1, F_1, D_1) → poly18, d_8, m_4, f_6Polygon(M_1, E_1, G_1, F_1) → poly19, m_5, e_8, g_6, f_7Translate(M_1, Vector[(Move / π * v_2)]) → N_1Translate(F_1, Vector[(Move / π * v_2)]) → O_1Translate(D_1, Vector[(Move / π * v_2)]) → P_1Polygon(N_1, O_1, P_1) → poly18', p_3, n_3, o_3Line(M_1, E_1) → q_3OrthogonalLine(G_1, q_3) → r_3Intersect(q_3, r_3) → Q_1Polygon(M_1, F_1, G_1, Q_1) → poly20, m_6, f_8, g_7, q_4Midpoint(D_1, H_1) → R_1Vector(R_1, D_1) → w_2Vector(R_1, H_1) → u_3Midpoint(M_1, F_1) → S_1Vector(S_1, M_1) → v_3Vector(S_1, F_1) → w_3Line(M_1, F_1) → s_3Line(Q_1, G_1) → t_3Point(s_3) → T_1OrthogonalLine(T_1, t_3) → i_4Intersect(t_3, i_4) → U_1Midpoint(T_1, U_1) → V_1Vector(V_1, T_1) → u_4Vector(V_1, U_1) → v_4Point(h_3) → W_1OrthogonalLine(W_1, l_3) → j_4Intersect(l_3, j_4) → Z_1Midpoint(W_1, Z_1) → A_2Vector(A_2, W_1) → w_4Vector(A_2, Z_1) → k_4Line(B_2, C_2) → n_4Line(D_2, n_4) → p_4Point(p_4) → E_2Segment(D_2, B_2) → r_4Segment(E_2, C_2) → s_4Segment(D_2, E_2) → t_4Segment(B_2, C_2) → i_5Point(n_4) → F_2OrthogonalLine(F_2, p_4) → j_5Intersect(p_4, j_5) → G_2Midpoint(E_2, C_2) → H_2OrthogonalLine(B_2, p_4) → k_5Point(k_5) → L_2OrthogonalLine(L_2, k_5) → l_5OrthogonalLine(C_2, l_5) → n_5Intersect(l_5, n_5) → M_2Midpoint(G_2, F_2) → K_2Midpoint(L_2, M_2) → N_2OrthogonalLine(D_2, i_5) → p_5OrthogonalLine(E_2, i_5) → q_5Vector(N_2, L_2) → u_5Vector(N_2, M_2) → v_5Vector(K_2, F_2) → t_5Vector(K_2, G_2) → u_6Polygon(D_2, B_2, C_2, E_2) → poly21, d_9, b_6, c_7, e_9Rotate(D_2, (-Move), H_2) → I_2Rotate(B_2, (-Move), H_2) → J_2Rotate(C_2, (-Move), H_2) → R_2Rotate(E_2, (-Move), H_2) → S_2Polygon(I_2, J_2, R_2, S_2) → poly21', i_6, j_6, r_6, s_6Segment(I_2, S_2) → k_6OrthogonalLine(I_2, j_6) → l_6OrthogonalLine(L_2, l_6) → n_6Intersect(l_6, n_6) → T_2OrthogonalLine(J_2, n_6) → p_6Midpoint(L_2, T_2) → V_2Vector(V_2, L_2) → v_6Vector(V_2, T_2) → w_6OrthogonalLine(F_1, f_8) → r_5OrthogonalLine(G_1, f_8) → s_5Point(r_5) → O_2OrthogonalLine(O_2, s_5) → q_6Intersect(s_5, q_6) → P_2Midpoint(O_2, P_2) → Q_2Vector(Q_2, O_2) → w_5Vector(Q_2, P_2) → t_6Segment(D_1, E_1) → a_7Segment(F_1, G_1) → h_7Segment(F_1, D_1) → b_7Segment(G_1, E_1) → i_7Segment(U_2, W_2) → j_7OrthogonalLine(Z_2, j_7) → k_7Intersect(k_7, j_7) → A_3Rotate(Z_2, 180*°, A_3) → B_3Segment(Z_2, U_2) → l_7Segment(U_2, B_3) → m_7Segment(B_3, W_2) → n_7Segment(W_2, Z_2) → p_7Line(U_2, W_2) → q_7Point(q_7) → C_3Point(k_7) → D_3Line(C_3, k_7) → r_7Line(D_3, q_7) → s_7Intersect(r_7, s_7) → E_3Line(B_3, q_7) → t_7Line(W_2, k_7) → a_8Intersect(s_7, a_8) → F_3Intersect(r_7, t_7) → G_3Line(Z_2, q_7) → b_8Intersect(r_7, b_8) → H_3Midpoint(H_3, G_3) → I_3Midpoint(E_3, F_3) → J_3Vector(J_3, E_3) → u_7Vector(J_3, F_3) → v_7Vector(I_3, H_3) → w_7Vector(I_3, G_3) → u_8Polygon(U_2, A_3, Z_2) → poly22, z_3, u_9, a_9Polygon(U_2, B_3, A_3) → poly23, a_{10}, u_{10}, b_9Polygon(A_3, W_2, B_3) → poly24, b_{10}, a_{11}, w_8Polygon(A_3, Z_2, W_2) → poly25, w_9, a_{12}, z_4Mirror(U_2, l_7) → K_3Mirror(A_3, l_7) → L_3Mirror(Z_2, l_7) → M_3Midpoint(Z_2, A_3) → N_3Midpoint(U_2, Z_2) → O_3Midpoint(Z_2, W_2) → P_3Segment(O_3, N_3) → c_8Segment(N_3, P_3) → g_8Mirror(U_2, c_8) → Q_3Mirror(A_3, c_8) → R_3Mirror(Z_2, c_8) → S_3Polygon(Q_3, R_3, S_3) → poly22', s_8, q_8, r_8Mirror(A_3, g_8) → T_3Mirror(Z_2, g_8) → U_3Mirror(W_2, g_8) → V_3Polygon(T_3, U_3, V_3) → poly25', v_8, t_8, u_{11}Midpoint(U_2, A_3) → W_3Rotate(Q_3, (-o_5), W_3) → Z_3Rotate(R_3, (-o_5), W_3) → A_4Rotate(S_3, (-o_5), W_3) → B_4Polygon(Z_3, A_4, B_4) → poly22'', b_{11}, z_5, a_{13}Midpoint(A_3, W_2) → C_4Rotate(T_3, o_5, C_4) → D_4Rotate(U_3, o_5, C_4) → E_4Rotate(V_3, o_5, C_4) → F_4Polygon(D_4, E_4, F_4) → poly25'', f_9, d_{10}, e_{10}Segment(U_2, W_2) → h_8Segment(Z_2, B_3) → i_8OrthogonalLine(U_2, b_8) → j_8Intersect(b_8, j_8) → G_4Intersect(t_7, j_8) → H_4Intersect(t_7, a_8) → I_4Intersect(a_8, b_8) → J_4Polygon(G_4, J_4, I_4, H_4) → poly26, g_9, j_9, i_9, h_9Segment(A, B) → k_8Segment(B, C) → l_8Segment(C, A) → m_8Angle(J_4, G_4, H_4) → ζAngle(H_4, I_4, J_4) → ηAngle(G_4, H_4, I_4) → θAngle(I_4, J_4, G_4) → ιAngle(H_1, D_1, E_1) → κAngle(E_1, L_1, H_1) → λAngle(L_1, H_1, D_1) → μAngle(D_1, E_1, L_1) → νAngle(F_1, M_1, Q_1) → ξAngle(Q_1, G_1, F_1) → οAngle(G_1, F_1, M_1) → ρAngle(M_1, Q_1, G_1) → σAngle(B, U, O) → τAngle(O, C, B) → υAngle(C, B, U) → ϕAngle(U, O, C) → χAngle(B, I, J) → ψAngle(I, J, C) → ωAngle(C, B, I) → α_1