Answer:
Reason 2: Alternate interior
Statement 4: AC = CA
Reason 4: They are lengths of the same segment.
Explanation:
Statement 2

Reason 2
A transversal is a line that intersects two or more parallel lines. When a transversal intersects a pair of parallel lines, it creates several angles.
In the given parallelogram ABCD, line segment AC is the transversal. It intersects both pairs of parallel lines.
Alternate interior angles are a pair of angles that are on opposite sides of the transversal and inside (between) the two parallel lines.
In the given parallelogram ABCD, angles 1 and 3 are on opposite sides of the transversal and inside the parallel lines. Similarly, angles 2 and 4 are on opposite sides of the transversal and inside the parallel lines.
According to the Alternate Interior Angles Theorem, if two parallel lines are cut by a transversal, then the alternate interior angles are equal.
Therefore, we can use the Alternate Interior Angles Theorem to prove that angles 2 and 4 are congruent.
The correct reason for statement 2 is:
- When a transversal crosses parallel lines, alternate interior angles are congruent.

Statement 4
AC = CA
Reason 4
From inspection of parallelogram ABCD, we can see that triangle ABC and triangle CDA share a common side: line segment AC.
The Reflexive Property of Congruence states that any line segment is congruent to itself.
Therefore, the correct reason for statement 4 is:
- They are lengths of the same segment.