In the scenario described, angle 5 is located on the upper side of line N and to the left, while angle 1 is located on the upper side of line M and also to the left, across from angle 5, but on a different parallel line. Since angles 1 and 5 are both situated outside the parallel lines (one above M and the other above N) and lie on opposite sides of the transversal (the inclined line), they are classified as alternate exterior angles.
Therefore, the correct answer is: alternate exterior angles.