1. WARMUP TEXTBOOK P. 18 #35-53 ODD

2. SEGMENTS AND SEGMENT ADDITION AGENDA: WARMUP SEGMENT NOTES/PRACTICE QUIZ THURSDAY UNIT 2 TEST WEDNESDAY (2/18)

3. Segment Segment AB contains points A and B and the set of all points between A and B. Notation: AB A B Order Doesn’t Matter AB and BA are the same.

4. Ray Notation: AB A B Ray AB - A ray has one endpoint and continues on forever in one direction. Order DOES Matter AB and BA are NOT the same.

5. Length The Length of AB is the distance between points A and B. Notation: AB 1. Can you find the length of a line? Example: AB = 5 inches AB 5in No! 2. Can you find the length of a ray?

6. Notice the difference in notation for each… Notation Line ABAB Segment ABAB Ray ABAB The length of ABAB

7. Congruent In geometry, two figures that have the same shape and size are congruent. Example: Congruent segments would have equal lengths. Notation:  AB  CD AB = CD A B C D 5in

8. Midpoint of a Segment The midpoint of a segment is the point that divides a segment into two congruent segments. A B C If C is the midpoint of AB, then AC  CB.

9. Segment Bisector A segment bisector is a line, segment, ray, or plane that intersects the given segment at its midpoint. A B C D FD is the segment bisector of AB. C is the midpoint of AB. F

10. Algebra Connection AB C Given that C is the midpoint of AB, find x. 2x - 35x - 24 Because C is the midpoint, AC  CB and AC = CB. Use this information to set up an algebraic equation: AC = CB 2x – 3 = 5x – 24 Now solve for x. -3 = 3x – 24 21 = 3x 7 = x

11. Algebra Connection AB C Given that C is the midpoint of AB, find x. 5x + 17x - 7 AC = CB 5x + 1 = 7x – 7 1 = 2x – 7 8 = 2x 4 = x Second Example

12. Segment Addition Postulate- If B is between A and C, then AB + BC = AC. AC B Ex. If AB = 10 inches and BC = 8 inches, then AC = 18 inches.

13. Algebra Connection AB C 6x - 10x - 1 Given that AB = 24, solve for x, AC and CB. AC + CB = AB. 6x – 10 + x – 1 = 24 7x – 11 = 24 7x = 35 x = 5 AC = 6x – 10 AC = 6(5) – 10 AC = 20 CB = x – 1 CB = 5 – 1 CB = 4 NEVER TRUST DIAGRAMS! Third Example

14. Algebra Connection DG F 3x + 42x Given DG = 7x - 2, solve for x, DF, FG, and DG. DF + FG = DG. 3x +4 + 2x = 7x - 2 5x + 4 = 7x - 2 4 = 2x - 2 3 = x DF = 3x + 4 DF = 3(3) + 4 DF = 13 FG = 2x FG = 2(3) FG = 6 Fourth Example 6 = 2x DG = 7x – 2 DG = 7(3) – 2 DG = 19