Area and Perimeter of Squares and Rectangles with Formulas

① This example visually demonstrates the area and perimeter formulas for squares and rectangles, allowing learners to see how changing side lengths affects these measurements. ② Core math concepts include plane geometry, area, perimeter, properties of squares and rectangles, and algebraic formula representation. ③ Construction details: Using GeoGebra commands such as Line, OrthogonalLine, Point, Intersect, and Polygon to create the shapes, with text objects (text1 to text4) displaying formulas and computed values; objects include vertices A, B, C, D, E, F, G, H, edges f, g, h, i, j, k, l, m, and polygons poly1 and poly2. ④ Suitable for upper elementary to middle school students learning introductory geometry, and useful for classroom demonstrations or self-exploration by dragging vertices to observe numerical changes and reinforce formula understanding.