Answer:
with respect to transversal l, angles 6 and 12 are "alternate interior" angles
Step-by-step explanation:
Angles 6 and 12 are at different intersections. The line joining those intersections is line l.
The transversal is l.
__
With respect to that transversal, angle 6 is between lines m and n crossing that transversal. Likewise for angle 12. Since both are "inside" angles, they are "interior."
Angles 6 and 12 are on opposite sides of the transversal l, so are "alternate" angles.
Angles 6 and 12 are "alternate interior" angles.