Trapezoid Midsegment Dynamic Demonstration

① This GeoGebra example dynamically demonstrates the trapezoid midsegment (the segment connecting the midpoints of the two legs), showing that it is parallel to both bases and its length equals half the sum of the base lengths. ② Core mathematical concepts include trapezoids, midsegments, parallel lines, midpoints of segments, and length relationships, involving polygon geometry and basic measurement. ③ Construction details: Using GeoGebra commands such as Segment, Line, Point, Angle, and Midpoint, the trapezoid vertices A, B, C, D, the midpoints E and F on the legs, and the midsegment EF are constructed; multiple angles (α, β, γ, δ, ε, ζ) and segments (a, b, c, d, e, f, g, h, i, j) are labeled, along with a text object text1 for displaying measurements or explanations. ④ Suitable for middle school geometry teaching or self-study, to understand the trapezoid midsegment theorem, and as an interactive exploration tool to drag vertices and observe how the midsegment length changes relative to the bases.