Rectangle ABCD has four right angles.

1. What is the sum of its angle measures?

2. Move vertex A to a different location. Which vertex angle remains unchanged?

3. What is the sum of the angle measures of the quadrilateral? °

4. Move vertex B to a different location. What is the sum of the angle measures of the quadrilateral? °

5. Move vertices C and D to different locations.
What is the sum of the angle measures of the quadrilateral? °

6. Move each vertex one more time to a different location.
What is the sum of the angle measures of the quadrilateral? °

7. Make a conjecture. What is the sum of the angle measures of any quadrilateral? °