1. PARALLEL LINES & TRANSVERSALS Parallel Lines - lines in the same plane that will never intersect

2. Skew Lines - lines that do not intersect and are not in the same plane. Transversal - a line that intersects two or more lines in a plane

3. Interior Angles - angles that are between the lines Exterior Angles - angles that are outside the lines

4. Alternate Interior Angles - they are on opposite sides of the transversal Alternate Exterior Angles - they are on opposite sides of the transversal

5. Consecutive Interior Angles -They are sometimes called Same-Side Interior Angles - they are on the same side of the transversal

6. Corresponding Angles - they are an exterior and interior angle on the same side of the transversal but not adjacent angles.