Definition:Transversal (Geometry)

Definition
A transversal of two lines lying in the same plane is a line which intersects them in two different points.

The transversal is said to cut the two lines that it crosses.


 * Alternate Interior Angles.png

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

In the above figure,$$\angle AEF$$, $$\angle CFE$$, $$\angle BEF$$, and $$\angle DFE$$ are interior angles.

Alternate Interior Angles
Alternate interior angles are the angles which are between two lines cut by a transversal, on opposite sides and different lines.

In the above figure, $$\angle AEF$$ and $$\angle DFE$$ are a pair of alternate interior angles, as are $$\angle CFE$$ and $$\angle BEF$$.

Corresponding Angles
Corresponding Angles are the angles in equivalent positions on the two lines cut by the transversal with respect to the transversal.

For example, $$\angle AEF$$ and the angle from $$C$$ to $$F$$ and then down along $$EF$$ are corresponding angles.