1. SEGMENT ADDITION
This stuff is AWESOME!

2. Lesson 1-2: Segments and Rays
Between
Definition: X is between A and B if AX + XB = AB.
AX + XB = AB
Notice that this does not say X is in the middle of A and B; it is just somewhere between A and B. Therefore AX may not equal XB
Lesson 1-2: Segments and Rays

3. The Segment Addition Postulate
If C is between A and B, then AC + CB = AB.
Example:
If AC = x , CB = 2x and AB = 12, then, find x, AC and CB. 2x x 12
Step 1: Draw a figure
Step 2: Label fig. with given info.
AC + CB = AB
x x = 12
3x = 12
x = 4
Step 3: Write an equation
x = 4
AC = 4
CB = 8
Step 4: Solve and find all the answers
Lesson 1-2: Segments and Rays

4. Lesson 1-2: Segments and Rays
Congruent Segments
Definition:
Segments with equal lengths. (congruent symbol: )
Congruent segments can be marked with dashes.
If numbers are equal the objects are congruent.
AB: the segment AB ( an object )
AB: the distance from A to B ( a number )
Correct notation:
Incorrect notation:
Lesson 1-2: Segments and Rays

5. Lesson 1-2: Segments and Rays
Bisect
To cut into two equal parts.
FOR SEGMENTS: Any segment, line or plane that divides into two congruent parts, intersecting the segment at it’s midpoint.
Definition:
Lesson 1-2: Segments and Rays

6. Q is between R and T. RT = 18 and QR = 10. Find QT.
N is between L and P. LN = 14 and PN = 12. Find LP. L 14 N 12 P
Q is between R and T. RT = 18 and QR = 10. Find QT. 10 R Q T 18

7. Find MN if N is between M and P, MN = 3x + 2, NP = 18, and MP = 5x.
3x = 5x
3x + 20 = 5x
-3x x
20 = 2x
10 = x

8. You Try!!!
B is between A and C. Find the value of x and the measure of BC if: AB = 3, BC = 4x + 1, AC = 8.
Y is between X and Z, find the value of x and the measure of XZ. XY = 24, YZ = 3x, XZ = 7x – 4.
If M is between L and N and LM = 2, MN = 4x + 6, LN = 32, then find x and MN.
If F is between E and G and EF = 26, FG = 5x, EG = 9x –6, find x and EG.
x=1, BC=5
x=7, XZ=45
X=6, MN=30
X=8, EG= 66