Area Trisection of Parallelogram DEFH
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Dissecting a Triangle Into Three Equal Areas
This example demonstrates constructing a parallelogram DEFH where DE is one-third of BC and EF is half the length of the median from vertex A. Key mathematical concepts include similar triangles, median properties, and proportions. GeoGebra commands used include Polygon, Midpoint, Dilate, Segment, Line, and Intersect. Suitable for middle school and above students learning geometric construction.
GeoGebra Commands & Parameters
Polygon(A, B, C) → poly1, c, a, bMidpoint(B, A) → D_1Midpoint(A, C) → E_1Dilate(B, 0.3333333333333333, C) → EDilate(B, 0.6666666666666666, C) → DSegment(D_1, E_1) → H_1Midpoint(B, C) → F_1Segment(A, F_1) → eLine(D, e) → fLine(E, e) → gIntersect(g, H_1) → FIntersect(f, H_1) → HPolygon(D, E, F, H) → poly2, d, e_1, f_1, hMidpoint(f_1) → IPolygon(A, B, D, H, I) → poly3, a_1, b_1, d_1, h_1, iPolygon(A, I, F, E, C) → poly4, a_2, i_1, f_2, e_2, c_1PointIn(poly4) → Pointpoly4PointIn(poly3) → Pointpoly3PointIn(poly2) → Pointpoly2