Definition:Transversal (Geometry)/Exterior Angle

Definition

 * Alternate Interior Angles.png

Exterior angles are the angles which are not between the two lines cut by a transversal.

In the above figure, the exterior angles with respect to the transversal $EF$ are:
 * $\angle AHE$
 * $\angle CJF$
 * $\angle BHE$
 * $\angle DJF$

Also see

 * Equal Corresponding Angles implies Parallel Lines