1. Angle Pairs Module A1-Lesson 4
Photos:

2. Complementary Angles Two angles whose measures have a sum of 90°.
Each angle is a complement of the other.

3. Supplementary Angles Two angles whose measures have a sum of 180°.
Each angle is a supplement of the other.

4. Adjacent Angles (review)
Two angles with a common vertex and side but no common interior points.

5. Vertical Angles
Two angles that are not adjacent and whose sides are formed by two intersecting lines.

6. Intersecting
The intersection of two or more figures is the point or points that the figures have in common.

7. Postulate 3-Intersection of Two Lines
Postulate 4-Intersection of Two Planes

8. Right Angle (review)
An angle with a measure of 90°.

9. Perpendicular Two lines that intersect to form a right angle.
The symbol for “perpendicular to” is .
The red angle mark
indicates a right angle.

10. Linear Pair
Two adjacent angles whose noncommon sides are on the same line.