To prove that quadrilateral ABCD is a rectangle using coordinate geometry, you should demonstrate that opposite sides are congruent and that the slopes of consecutive sides are opposite reciprocals.
A rectangle has the following properties:
- Opposite sides are congruent.
- The slopes of consecutive sides must be opposite reciprocals (meaning they are perpendicular).
Thus, the correct statement to use in this case is:
"Prove that opposite sides are congruent and the slopes of consecutive sides are opposite reciprocals."
This will confirm that quadrilateral ABCD has the necessary properties of being a rectangle.