1.5 Measuring Segments 2011
September 01, 2011
1.5 Measuring Segments
Objective: Find the lengths of segments.
1
1.5 Measuring Segments 2011
September 01, 2011
Warm­up
Simplify each absolute value expression.
1) |­6|
2) |3.5|
Solve each equation.
3) |7­10|
6) x + 2x ­ 6 = 6
4) |­4 ­ 2|
5) |­2 ­ (­4)|
7) 3x + 9 + 5x = 81
2
1.5 Measuring Segments 2011
September 01, 2011
Congruent Segments: Segments that have the same length.
Example:
3 cm
A
3 cm
B
C
D
Written as: AB ≅ CD
3
1.5 Measuring Segments 2011
September 01, 2011
Example: Find the lengths of the following segments. Tell whether the segments are congruent.
AD and BE
4
1.5 Measuring Segments 2011
September 01, 2011
Describe Segment Relationships
Step 1: Name all of the segments in the following figure.
X
Y
Z
Step 2: Describe the relationships between the different segments.
Step 3: What relationship always applies to a figure like this?
(Even if point Y was placed somewhere else between X and Z.)
5
1.5 Measuring Segments 2011
September 01, 2011
Example:
6
1.5 Measuring Segments 2011
September 01, 2011
Midpoint (of a segment): The point that divides the segment into two congruent segments.
Example: B is the midpoint of AC.
7
1.5 Measuring Segments 2011
September 01, 2011
Example:
8
1.5 Measuring Segments 2011
September 01, 2011
Homework:
page 33 (2 ­ 18 even, 30 ­ 36 even)
9