What Are the Characteristics of Parallelograms?

This GeoGebra applet, created by Chi Ming Ko (GeoGebra Academy, Hong Kong), explores the fundamental geometric properties of parallelograms. Using commands such as Midpoint, Rotate, Polygon, and Angle, the construction dynamically illustrates key characteristics: opposite sides are parallel and equal in length, opposite angles are equal, consecutive angles are supplementary, and diagonals bisect each other. Users can drag the vertices to observe how the figure changes while these properties remain consistent, allowing them to verify that these geometric theorems hold true for any parallelogram. The interactive design supports both classroom instruction and independent student exploration, making it a valuable tool for middle school geometry education. Through hands-on manipulation, learners develop an intuitive understanding of parallelogram properties and strengthen their ability to construct logical geometric proofs.