分配律的面积模型
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该范例通过面积模型演示了分配律。涉及的核心数学概念包括分配律和几何构造。使用了DynamicCoordinates, Polygon, Point, Segment, Midpoint, Distance, Intersect, If, Vector, Text等GeoGebra命令。适合初中及以上学生学习分配律和几何构造。
GeoGebra 命令及参数
DynamicCoordinates(A', If[x(A') < 6, 6, x(A')], If[y(A') < 6, 6, y(A')]) → APolygon(A, B, C, D) → q, s1, s2, s4, s3Point(s3) → V'Point(s4) → H'DynamicCoordinates(V', x(V'), floor(y(V'))) → VDynamicCoordinates(H', floor(x(H')), 0) → HSegment(H, H_1) → fSegment(V, V_1) → gMidpoint(B, V_1) → M1Midpoint(C, V_1) → M2Midpoint(B, H_1) → M3Midpoint(H_1, A) → M4Distance(B, V_1) → aDistance(V_1, C) → bDistance(B, H_1) → cDistance(H_1, A) → dIntersect(f, g) → IMidpoint(C, I) → M6Midpoint(V_1, H_1) → M5Midpoint(I, A) → M7Midpoint(H, V) → M8Polygon(H_1, B, V_1, I) → q2, h_1, b_1, v_1, iIf(Defined[Intersect[b_1, v_1]], Intersect[b_1, v_1], B) → EPolygon(I, E, C, H) → q3, i_1, e, c_1, hIf(Defined[Intersect[h_1, i]], Intersect[h_1, i], B) → FPolygon(A, F, I, V) → q4, a_1, f_1, i_2, vPolygon(V, I, H, D) → q1, v_2, i_3, h_2, d_1Vector(J, K) → uVector(K, J) → wVector(L, M) → jVector(M, L) → kMidpoint(J, K) → M9Midpoint(L, M) → M10Segment(J - (0, 0.5), J + (0, 0.5)) → lSegment(K - (0, 0.5), K + (0, 0.5)) → mSegment(M - (0.5, 0), M + (0.5, 0)) → nSegment(L - (0.5, 0), L + (0.5, 0)) → pMidpoint(C, A) → M0If(eval, Text[((a + b) * (c + d))], "" + (a + b) + "×" + (c + d) + "") → text11If(eval, Text[(a * c)], "" + a + "×" + c + "") → text5If(eval, Text[(b * c)], "" + b + "×" + c + "") → text7If(eval, Text[(a * d)], "" + a + "×" + d + "") → text6If(eval, Text[(b * d)], "" + b + "×" + d + "") → text8Text(((a + b) * (c + d))) → textArea