SECTION 2.1Segment Bisectors

LEARNING TARGETS:1. I will be able to use the Midpoint Formula.2. I will be able to identify segment bisectors and find segment lengths.

VOCBAULARYMidpoint, Bisect, Segment Bisector

What’s the Chapter About?

• Analyzing segment bisectors and angle bisectors.

• Identifying complementary angles, supplementary angles, vertical angles, and linear pairs.

• Using properties of equality and congruence.

Essential Questions

1. How do you identify special angle and segment relationships?

2. How would you describe the relationship between equality and congruence?

3. How are conditional statements necessary to logical reasoning?

Chapter Readiness Quiz

Geo-Activity

Geo-Activity

Geo-Activity

Geo-Activity

Midpoint

• MIDPOINT:• The point on a segment that divides the

segment into two congruent segments.\• Point M is the midpoint below:

AM

B

Segment Bisector• SEGMENT BISECTOR:

• A segment, ray, line, or plane that intersects a segment at its midpoint.

• To bisect a segment means to divide the segment into two congruent segments.

Example (Notes)

1. K is the midpoint of FG. Find FK and KG.

FK =

KG =

Example (Textbook)

Example (Notes)

2. M is the midpoint of JL. JM = 7. Find ML and JL.

ML =

JL =

Example (Textbook)

PS =

RS =

Example (Notes)

• Line s is a segment bisector of FH. Find each value of x.

Midpoint Formula• The Midpoint Formula:

• The coordinates of the midpoint of a segment are the averages of the x-coordinates and y-coordinates of the endpoints.

• The midpoint of the segment joining A(x1, y1) and B(x2, y2) is…

More Midpoint Formula

Example (Notes)• Sketch segment GH.

• Then find the midpoint of GH using the Midpoint Formula.

Example (Notes)• Sketch segment GH.

• Then find the midpoint of GH using the Midpoint Formula.

Example (Notes)

Map of City

Cooperative Learning

•Midpoint Formula Worksheet

HOMEWORK•Section 2.1 Assignment

•Page 56 #11-32, 36-39, and 42-45

•Due Tuesday, 10/18