Characteristics and Proofs of a Parallelogram: Identifying and defining elements

To determine the type of angles indicated in a parallelogram, it is crucial to understand the properties of the angles formed by its parallel sides. In any parallelogram, opposite sides are parallel. This means the angles on the same side of the transversal formed by these parallel lines are co-interior angles.

For a parallelogram $ABCD$, let's focus on the consecutive angles: angle $A$ and angle $D$, or angle $B$ and angle $C$. These consecutive angles are on the same side of the traversal created by the sides. According to the properties of a parallelogram, consecutive angles are supplementary, meaning they add up to $180^\circ$.

In the context of parallel lines and a transversal, such consecutive interior angles are known as "co-interior" angles. They are supplementary and occur when the traversal cuts across the parallel sides of the parallelogram.

Thus, the type of angles indicated in the figure for the parallelogram $ABCD$ are co-interior angles.

Therefore, the correct answer to this problem is Co-interior.