1. Angle
Relationships

2. Parallel Lines Definition: Example:
2 lines in the same plane that do not intersect
Example:
m // n m n

3. Perpendicular Lines Definition: Example:
2 lines that intersect to form a right angle
Example: m n

4. Adjacent Angles Definition: Example: or
2 angles that share a common side and vertex, but do not overlap
Example: or A B C D 1 2

5. Vertical Angles Definition: Example:
When 2 lines intersect, they form 2 pairs of opposite angles called vertical angles.
Vertical angles are congruent, or equal in measure.
Example: 1 2 3 4

6. Complementary Angles Definition: Example:
2 angles whose measures add up to 90o.
Check using the corner of your paper
Example: 1 2

7. Supplementary Angles Definition: Example:
2 angles whose measures add up to 180o.
Check using the straight side of your paper
Example: 1 2

8. Angles in a Triangle Definition: Example:
The measures of the interior angles in a triangle add up to 180o.
Example: A C B

9. C D A B I J E F V W X O P M N Q R