1. Parallel lines and Triangles Intro Vocabulary
Unit 7
Parallel lines and Triangles Intro Vocabulary

2. Segment
-part of a line cut off by two points
Notation:

3. Line - connected points that extend infinitely in two directions
Notation:

4. Angle -space formed between two rays that meet at a common endpoint
Notation:

5. Congruent
- figures of both the same size and same shape
Symbol:

6. -Segments which have equal lengths Notation:
Congruent Segments
-Segments which have equal lengths Notation:

7. -point that divides a segment into two congruent segments
Midpoint
-point that divides a segment into two congruent segments

8. -Line (or part of a line) that intersects the segment at its midpoint
Segment Bisector
-Line (or part of a line) that intersects the segment at its midpoint

9. -Lines that intersect to form a right angle
Perpendicular Lines
-Lines that intersect to form a right angle
Symbol:___________

10. Perpendicular Bisector
-Line that is perpendicular to a segment at its midpoint

11. -Angles which have equal measures
Congruent Angles
-Angles which have equal measures

12. -Ray that divides an angle into two congruent angles
Angle Bisector:
-Ray that divides an angle into two congruent angles

13. Complementary Angles:
-set of angles whose measures sum to 90°

14. -set of angles whose measures sum to 180° (make a straight line)
Supplementary Angles
-set of angles whose measures sum to 180° (make a straight line)

15. Linear Pair
-Two adjacent angles whose non-common sides are opposite rays
* Postulate: Linear Pairs are supplementary

16. Vertical Angles
-Opposite (non-adjacent) angles formed by two intersecting lines
*Theorem: All vertical angles are congruent

17. Right Angles -Angle whose measure equals 90°
*Theorem all right angles are congruent

18. -Triangle that contains a right angle
Right Triangle
-Triangle that contains a right angle

19. Reflexive Property of Congruence
-A geometric figure is congruent to itself

20. Transitive Property of Congruence
-If two “things” are equal to the same amount, then the two “things” are equal to each other
Ex. Let a = 2 and b = 2. We know a = b by the Transitive Property of Congruence (both equal 2)