7 terms

PICTURE FOR THIS SET AT http://www.mathnstuff.com/math/spoken/here/2class/260/trans.htm UNDER A LINE CROSSES A PARALLEL LINE.

transversal

A line that crosses two or more other lines in the same plane.

corresponding angles

Angles in the same relative positions on each of the lines in comparison to the transversal. Example: Angle 2 and 6.

alternate interior angles

Angles between the lines and on opposite sides of the transversal. Example: Angle 3 and 6.

alternate exterior angles

Angles outside the lines, and on opposite sides of the transversal. Example: Angle 1 and 8.

consecutive interior angles

Angles which share the same side of the transversal and are between the lines.

consecutive exterior angles

Angles which share the same side of the transversal and are outside the lines.

converse

A postulate or theorem with the "if" and "then" parts reversed.