Angle
two rays with a common endpoint
Vertex
common endpoint of an angle
Acute angles
angles that are less than 90 degrees
Right angle
an angle that measures exactly 90 degrees
Obtuse Angle
An angle that measures more than 90 degrees but less than 180 degrees
Straight Angle
an angle that measures exactly 180 degrees
Congruent Angles
angles that have the same measure
Supplementary Angles
Two angles whose sum is 180 degrees
Complimentary Angles
Two angles whose sum is 90 degrees
Transversal
a line that intersects two or more parallel lines
corresponding angles
angles in the same place on different lines
Alternate exterior angles
Angles that lay outside the parallel lines and are on opposite sides of the transversal; They are congruent.
Alternate interior angles
Angles that lay inside the parallel lines and are on opposite sides of the transversal; They are congruent.