Answer
Both parallelograms ABCD and DCFE are similar because the two conditions of similarity satisfied.
1- corresponding angles are congruent since segment $AB\parallel DC \parallel EF $.
2- sides are proportional to each other
$ \frac{AD}{DE}=\frac{BC}{CF}=\frac{AB}{DC}=1 $
Noting that, since the two transversals are parallel then by theorem the distance between any two parallel lines is the same. Therefore AB= DC = EF.
Work Step by Step
Since the drawing shows the parallelograms have congruent corresponding angles and congruent corresponding sides they are congruent parallelograms and therefore similar to each other.
