Alternate Interior Angles Vs Alternate Exterior Angles. Alternate exterior angles are those angles that have different vertices lie on the alternate sides of the transversal and are exterior to the lines. Similar to before angles 1 2 7 and 8 are EXTERIOR angles.
In the diagram below transversal l intersects lines m and n. Alternate exterior angles are created in the space outside the parallel lines on alternating sides. When two lines are crossed by a transversal the opposite angle pairs on the outside of the lines are alternate exterior anglesOne way to identify alternate exterior angles is to see that they are the vertical angles of the alternate interior anglesAlternate exterior angles are equal to one another.
If two lines in a plane are cut by a transversal so that any pair of alternate exterior angles is congruent the lines are parallel.
Angles between the bounds of the two parallel lines are interior angles again created by the transversal. Angles between the bounds of the two parallel lines are interior angles again created by the transversal. In this example these are two pairs of Alternate Exterior Angles. Geometry - Identifying Alternate Interior and Exterior Angles - YouTube.