Alternate Exterior Angles
The term alternate exterior angles is often used when two lines are cut by a third line, a transversal.
In the figure above, line t is a transversal cutting lines k and l, and there are two pairs of alternate exterior angles:
1 and 7
4 and 6
The Alternate Exterior Angles Theorem states that if k and l are parallel, then the pairs of alternate exterior angles are congruent. That is,
1 
7
and
4 6.
The converse of this theorem is also true.
