1. Describe Angle Pair Relationships
1.5 GEOMETRY

2. Special Pairs of Angles
Vertical angles
Linear pair of angles
Complementary angles
Supplementary angles

3. Complementary Angles Definition: If two angles have a sum of 90o,
then the two angles are complementary angles.
Each angle is the complement of the other.
The angles themselves do not have to be adjacent,
but if they are, they must form a “perfect” corner.

4. Supplementary Angles Definition: If two angles have a sum of 180o,
then the two angles are supplementary angles.
Each angle is the supplement of the other.
The angles themselves do not have to be adjacent,
but if they are, they must form a straight line.

5. Adjacent angles O A C D DOC is adjacent to COA
DOA is NOT adjacent to COA

6. Linear Pair Definition: If two angles are adjacent and their noncommon
Sides are opposite rays, then the two angles form a linear pair.
LINEAR PAIR POSTULATE:
If two angles for a linear pair, then
They are supplementary
The sum of their measures is 180o.

7. Vertical Angles Definition: If two angles have their sides
that form two pairs of opposite rays, then the
two angles are vertical angles.
VERTICAL ANGLES THEOREM:
If two angles are vertical angles, then they are congruent.