Warm-up

• If M is the midpoint, find AM and MB

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Geometry Chapter 2

2.1: Segment Bisectors

Objective: Define segment bisector and use to find lengths of segments.Find midpoints of segments in the coordinate plane.

• Midpoint: A point on a segment that divides it into 2 congruent segments

– Example F

______ is the midpoint of DF

D

• Segment Bisector: A segment, ray, line, or plane that intersects a segment at its midpoint

• Bisect: To divide a segment into 2 congruent segments.

• Example:

__________

• Practice: • M is the midpoint of the segment.• 1)

2)

• Line l bisects the segment. Find the value of x.

Midpoints in the Coordinate Plane

• Midpoint Formula: The coordinates of the midpoint of a segment are the ____________

of the _____________ and the ____________ of the endpoints.

– If the coordinates of the endpoints are A (x1, y1) and B (x2, y2). Then the midpoint is at:

• Example: Find the coordinates of the midpoint of the indicated segment.

• AB with A(1,2), B(7,4)