1. Chapter 1 - Section 3 Special Angles

2. Supplementary Angles Two or more angles whose sum of their measures is 180 degrees. These angles are also known as linear pairs. The difference: Supplementary angles do not have to share a side, linear pairs do.

3. Complementary Angles Two or more angles whose sum of their measures is 90 degrees.

4. Adjacent Angles Angles that are next to each other and share a side.

5. Vertical Angles Angles that are across from each other. Formed by intersecting lines. Vertical angles are congruent.

6. Midpoint of a Segment The middle point of a segment. It divides the segment into two equal parts. Midpoint

7. Perpendicular Two lines or segments that intersect to form a 90 degree angle.

8. Perpendicular Bisector A line, segment, or ray that intersects a segment at its midpoint and forms a 90 degree angle. Perpendicular bisector