Properties of parallelograms
You should already know what a parallelogram is and it's basic characteristics. Below is a definition and four theorems that deal with characteristics of parallelograms, if you need to, add any important details to your Ch. 8 Vocabulary sheet. All four of the following theorems are also on your Ch. 8 Postulates & Theorems sheet.
There are two other important characteristics of parallelograms. One dealing with their consecutive interior angles and the other dealing with their diagonals. You should remember that consecutive interiors angles are two angles on the same side that add up to 180 degrees. You should also remember what a diagonal is.