三角形面积动画演示 by Michael Borcherds
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该范例通过动画展示了三角形面积的计算方法。核心数学概念包括三角形面积公式和中线定理。使用了If, Point, Polygon, Semicircle, Intersect, Angle, Rotate, Element, Segment等GeoGebra命令。适合初中及以上学生学习几何作图和面积计算。
GeoGebra 命令及参数
If(animate < 1, 0, animate - 1) → animate2Point(xAxis) → APoint(xAxis) → BPolygon(A, B, C) → poly1, c, a, bSemicircle(C, B) → dPoint(d, 1 - animate) → GIntersect(f, g) → FIntersect(f, b) → RIntersect(f, a) → DAngle(G, D, C) → αRotate(F, α, R) → SElement(Sort[{H, R}], 2) → JRotate(F, (-α), D) → QRotate(D, (-α), D) → D'Rotate(R, α, R) → E'Rotate(E', (-α), D') → PIf(animate < 1, D, Element[Sort[{D, E}], 1]) → IRotate(C, (-α), D') → C'_2Rotate(D, (-α), D') → D'_1Polygon(D, E', C) → poly2, j, k, lRotate(C, (-α), D) → C'Rotate(C, α, R) → C'_1Segment(R, C) → hPolygon(D'_1, E, C'_2) → poly2', m, n, pPolygon(A, J, I, B) → poly4, q, s, t, eSegment(C, D) → iPolygon(A, H, R) → poly3, r, a_1, h_1Segment(C, F) → f_1