When a transversal intersects two other lines, eight angles are created. These angles relate in different ways depending on their relative positions.

Name	Description
Vertical Angles	Angles that lie on opposite sides of a point of intersection
Corresponding Angles	Angles that lie in the same position around different intersection points.
Alternate Interior Angles	Angles that lie between the lines on opposite sides of the transversal.
Alternate Exterior Angles	Angles that lie outside the lines on opposite sides of the transversal.
Same-Side Interior Angles	Angles that lie between the lines on the same side of the transversal.
Same-Side Exterior Angles	Angles that lie outside the lines on the same side of the transversal.

All these angles can be appreciated in the following diagram.