Click on Show Side Lengths, select point A or B and move it around.
1. What do you notice is always true about the side lengths?
Hide the side lengths, and click on Show Angle Measures. Now move around point A or B again.
2. What do you notice is always true about the angle measures?
Hide the angle measures, now show the slopes. Again Move around point A or B.
3. What is always true about the slopes?
4. What can you infer because of question 3?
Hide the slopes, and click on the "Show Lengths of BE, DE, CE, AE" and move point A or B again.
5. What do you notice is always true about these lengths?
6. This means the Diagonals __________ each other.
Hide the lengths, finally select "other angle measures", move points A or B.
7. List all pairs of congruent angles you see.
8. Label the angles you listed in question 7 with the following angle relationships: Vertical Angles, Alternate Interior Angles, Interior Angles on the Same Side/ Supplementary.
9. Using the picture, and your answers to this exercise, what are the properties of Parallelograms that are always true?