Visual Proof of Triangle Area Formula: Dissection into an Equivalent Parallelogr

This GeoGebra example presents a visual dissection proof of the triangle area formula A = (b · h) / 2. It shows how a triangle can be cut and rearranged—using midpoint, perpendicular, intersection, segment, line, and rotate operations—to form an equivalent parallelogram with the same base and height, proving that the triangle’s area is half the parallelogram’s area. Key mathematical concepts include triangle area, parallelogram area, equidecomposability, altitude, base-height relationship, and geometric construction. The construction relies on GeoGebra commands Polygon, OrthogonalLine, Intersect, Midpoint, Segment, Line, and Rotate, involving objects such as vertices A, B, C, altitude foot H, and auxiliary points D, E, F. It is ideal for middle school geometry lessons, area formula derivation, teacher preparation, and student-centered exploration of transformations and area invariance.