3. 1.3 M EASURING S EGMENTS Objective: Students will find measures of segments. Correct notation will be used.

4. L INE S EGMENTS Since segments have 2 endpoints, it can be measured. Line segments are named with two capital letters that correspond to the 2 endpoints. When segments have the same measure, they are said to be congruent. (The same number of tick marks on a segment show congruence)

5. C ALCULATE M EASURES On line AC, if B is between A and C, then A, B, and C are collinear and the following things are true AB + BC = AC AC – AB = BC AC – BC = AB A C B

6. E XAMPLES Find all segments if Y is between X and Z. (find XY, YZ, XZ 1. XY = 5a, YZ = a, and XY = 25 2. XY = 12, YZ = 2c, and XZ = 28 3. XY = 2m+1, YZ = 6m, and XZ = 81 4. Find the value of all segments if L is between N and M, NL= 6x-5, LM= 2x+3, and NM= 30.