Copy of Theorem 09 - Opposite Sides and Angles in a Parallelogram
This shows that the opposite sides of a parallelogram are always equal in length and the opposite angles are also equal.
Click and drag the side [AB] or the side [AD] to change the shape of the parallelogram.
What do you notice about the adjacent angles?
Change the diagram so that all four sides are equal in length. What is this figure called?