Proving Quadrilaterals are Parallelograms

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.

TabletClass Math Proving Quadrilaterals Parallelograms Lesson from John Zimmerman on Vimeo.