In this lesson I will teach you how to prove a quadrilateral is a parallelogram. Of course not every quadrilateral is a parallelogram so it’s important for you to know how to identify and prove a quadrilateral is in fact a parallelogram. Now, why would you care if a quadrilateral is or is not a parallelogram? Well, one good reason is that once we know a figure is in fact a parallelogram we know a lot about it’s properties and features- this information can really help use solve problems. Hence, you want to know methods of proving a quadrilateral is a parallelogram and that’s our focus in this lesson. As you will see in the video, we will be using lots of theorems to prove a quadrilateral is a parallelogram. The basic idea is you will look at a quadrilateral and see if it matches the properties of a parallelogram- if it does than you can prove the quadrilateral to be a parallelogram. Don’t forget the previous lessons on how to plan and write a proof as it will help you a lot with this topic. Finally, take great notes and keep reviewing course material as the concepts build on each other.