Deriving the Area of a Trapezoid

①This example demonstrates how to derive the area formula of a trapezoid through dynamic geometry, visually transforming the trapezoid into a shape with a known area formula (such as a parallelogram or rectangle). ②Core mathematical concepts include the trapezoid area formula, bases, height, midsegment, and the idea of area conservation through geometric transformation. ③Construction: Based on the construction summary, GeoGebra commands such as Intersect, Point, and Segment are used to create vertices A, B, C, D and sides f, g, h, i, enabling auxiliary constructions for comparison. ④Suitable for middle school geometry lessons or self-study, helping learners understand the origin of the formula and develop geometric intuition and reasoning skills.