Question

describe a method to test whether a parallelogram is a rectangle, if you do not know the angle measures. to prove that a particular parallelogram is a rectangle, you can check if the choose... choose...

Explanation:

A rectangle is a special parallelogram with congruent diagonals. Since we cannot use angle measures, we rely on this key property unique to rectangles among parallelograms.

Answer:

1. diagonals of the parallelogram are congruent
2. (second confirmation: measure and compare the two diagonals to verify they are equal in length)

(Note: The two dropdowns correspond to the core property and its verification: first fill "diagonals are congruent", second can be "lengths of the diagonals are equal" to complete the method)