Algebraic Quadrilaterals: Constructing Quadrilaterals from Side Length Expressio

① This example demonstrates how to dynamically construct a quadrilateral based on algebraic expressions for its four side lengths, showing real-time updates of side measurements and shape. ② Core math concepts include algebraic expressions, linear equations, quadrilateral properties, geometric construction, and parametric thinking, with extensions to roots, probability, and logic. ③ Construction highlights: using GeoGebra commands such as Circle, Point, Segment, Intersect, Polygon, Midpoint, Textfield, and Random, with objects s_1 to s_4 as side-length variables, InputBox1-4 for editing expressions, presets and random buttons for generating different combinations, and polygon poly1 with sides AB, BC, CD, DA forming the dynamic quadrilateral. ④ Suitable for middle and high school algebra-geometry integration, helping students explore how side-length changes affect quadrilateral shapes and fostering algebraic modeling and geometric intuition.