Question

given quadrilateral defg is a parallelogram. what is the reason for step 5 in this proof? a. vertical angles theorem b. opposite interior angles of a parallelogram are congruent c. all angles of a rectangle have the same measure d. alternate interior angles theorem

Explanation:

The Vertical Angles Theorem states that when two lines intersect, the opposite (vertical) angles are congruent. In a parallelogram, when its diagonals intersect, vertical - angle pairs are formed. Opposite interior angles of a parallelogram refer to the non - adjacent interior angles between parallel sides. A rectangle is a special case of a parallelogram and the statement about all angles of a rectangle is not relevant here as we are dealing with a general parallelogram. The Alternate Interior Angles Theorem is about angles formed by a transversal and parallel lines. Since we are likely dealing with angles formed by the intersection of the diagonals of the parallelogram, the Vertical Angles Theorem is the most appropriate.

Answer:

A. Vertical Angles Theorem