A-2 Segment Addition & Congruence Notes

Intro: Write down two different ways to find the distance between the two points A and B on the number line.

→Finding the length of a segment

Example: Find the length of each segment using the points and number line below.

a. AB =

b. AC =

c. BD=

d. AD =

e. If E is the midpoint of AD, where would it be located? Plot it on the number line.

f. What do you notice about the lengths of AB, BD, and AD?

Segment Addition Postulate

If points A, B and C are collinear with B between A and C, then…

Example:

Example: Find x, QR, and QS in the diagram.

Example: B is between A and C. AB = x, BC = 3x + 1, and AC =25. Find x, the length of 𝐴𝐵̅̅ ̅̅ , and BC.

Example: Solve for x, then find EF.

Example: Point Z is the midpoint of XY. If XZ = 6x-1 and ZY= 2x+11, solve for the value of x, and find XY.

Example: Ms. Mathews is driving to Gilmore to visit a college friend. If she wants to stop for lunch when she’s about

halfway there, in which town should she plan to stop? Explain.