Parallel Lines and Transversas
vertical angles
Angles opposite one another at the intersection of two lines. These angles are congruent. Examples: Angle 1 and Angle 3 are vertical angles Angle 8 and Angle 6 are vertical angles
same side exterior angles
Exterior angles on the same side of the transversal cutting across 2 parallel lines. These angles are supplementary. Example: Angle 2 and Angle 8 are same side exterior and their sum is 180 degrees
same side interior angles
If the angles are on same side of the transversal and inside the 2 parallel lines then their sums ARE SUPPLEMENTARY. Example: Angle 3 and angle 5 are same side interior and their sum is 180 degrees
alternate exterior angles
If two parallel lines are cut by a transversal, then the alternate exterior angles are congruent. Example: angle 1 and angle 8 are alternate exterior angles
alternate interior angles
If two parallel lines are cut by a transversal, then the alternate interior angles are congruent. Example: angle 3 and angle 6 are alternate interior
corresponding angles
A pair of angles which are on the same side of the transversal, one must be interior, one must be exterior, and they must be nonadjacent. Corresponding angles are supplementary and are only formed when the lines are parallel. Example: Angle 3 and Angle 7 are corresponding Angle 2 and Angle 6 are corresponding
linear pair
Adjacent, supplementary angles. Excluding their common side, a linear pair forms a straight line. Examples: Angle 1 and Angle 4 are a linear pair. Angle 5 and Angle 6 are a linear pair. Angle 3 and Angle 4 are a linear pair.