**Geometry Chapter 1.6 Angle Pair Relationships**

**I) Vocabulary**

**A) Vertical Angles**: is when the sides of 2 angles form 2 pairs of opposite rays.

1. Vertical angles are congruent.

**B) Linear Pair**: 2 adjacent angles are a linear pair if their noncommon sides are opposite rays.

1. If two angles form a linear pair, then they are supplementary.

2. If two angles form a linear pair, then their sum is 180 degrees.

**C) Complementary Angles:**2 angles whose measures total 90 degrees.

1. If two angles have the same complement, then the 2 angles are congruent.

2. If two angles are complementary to congruent angles, then the two angles are congruent.

**D) Supplementary Angles**: 2 angles whose measures total 180 degrees.

1. If two angles have the same supplement, then the 2 angles are supplementary.

2. If two angles are supplementary to congruent angles, then the two angles are supplementary.