1-2 Linear 1-2 Linear MeasureMeasure

Textbook page 13

Review: Measuring with a Review: Measuring with a rulerrulerFind the length of using each ruler.

cm

in

Measuring a SegmentMeasuring a Segment

• 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.

AB

C

More ExamplesMore Examples

1. Find XY.

2. Find FG.

Algebraic ExamplesAlgebraic Examples

3. Find x and MN if N is between M and P, MP = 60, MN = 6x - 7, and NP = 2x + 3.

Congruent SegmentsCongruent Segments

Definition:

AB: the segment AB (an object)

AB: the distance from A to B (a number)

AB

D

C

Congruent segments can be marked with dashes. Also, if the measurements are the same for two segments, then the segments are congruent.

Correct notation:

Incorrect notation:

AB = CD AB CD

AB = CDAB CD

Segments with equal lengths. (congruent symbol: )