1-3+Segments+&+Their+Measures

=1-3 Segments and Their Measures= Allie Snider

Summary:
This section will teach you how to measure line segments. One way to measure segments is using the Distance Formula. This section is in the textbook from pages 17-23.

Vocabulary for this section:
Postulates - rules in math that you don't have to prove; they are just accepted Theorems - rules in math that have to be proven Between - refers to 3 collinear points. One of the points is "between" the other two Congruent Segments - line segments whose lengths are the same

**Postulates/Theorems:**

 * ===**Ruler Postulate- states that points on a line can be substituted with real numbers. That real number is called the coordinate of that point.**===

(The name of a point can be point A but the coordinate of it can be X1)

The distance between J and K is the absolute value of the difference of coordinates J and K.

 * ===Segment Addition Postulate- 2 parts of a line segment equal the entire segment.===


 * ===Pythagorean Theorem===



SAMPLE PROBLEMS:
Find the distance between each set of points. S(0,6) T(8,12) 1)

2) A(1,-2) B(-2,-6)



Draw a sketch of the 3 collinear points. Then, write the Segment Addition Postulate for the points 3) W is between A and F



AW+WF=AF

PRACTICE PROBLEMS:
Use the Distance Formula to decide whether JK is congruent to KL. 1) J(0,-8) K(4,3) L(-2,-7)

Suppose M is between L and N. Use the Segment Addition Postulate to solve for the variable. Then, find the lengths of LM, MN, and LN. 2) LM= 7y+9 MN= 3y+4 LN= 143

Find the distance between the 2 points. 3) B(7, -5) D(3,0)

4) R(-12, 8) K(-7, 1)

[|http://www.purplemath.com/modules/distform.htm]

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