To determine the relationship between angle 3 and angle 6, we can analyze their positions in relation to the parallel lines (M and N) and the transversal.
- Angle 3 is located in the lower right position around line M.
- Angle 6 is located in the lower right position around line N, directly parallel to line M.
Since angle 3 and angle 6 are on opposite sides of the transversal and outside of the two parallel lines, they are classified as alternate exterior angles.
Therefore, the correct answer is:
alternate exterior angles.