Definition:Transversal (Geometry)/Interior Angle

Definition

 * Alternate Interior Angles.png

Interior angles are the angles which are between the two lines cut by a transversal.

In the above figure, the interior angles with respect to the transversal $EF$ are:
 * $\angle AHJ$
 * $\angle CJH$
 * $\angle BHJ$
 * $\angle DJH$

Also see

 * Supplementary Interior Angles implies Parallel Lines
 * Parallelism implies Supplementary Interior Angles