2. Angle Relationships Section 1-5

3. Adjacent angles Angles in the same plane that have a common vertex and a common side, but no common interior points. 1 2

4. Vertical angles two nonadjacent angles formed by two intersecting lines Vertical angles are congruent. 3 4

5. Linear pair adjacent angles whose noncommon sides are opposite rays The sum of the measures of the angles in a linear pair is 180. 56

6. Perpendicular lines special intersecting lines that form right angles Perpendicular lines intersect to form 4 right angles.

7. Supplementary angles – 2 angles whose measures have a sum of 180 Complementary angles – 2 angles whose measures have a sum of 90