1.4 Measuring Segments and Angles. Chapter 1 Tools of Geometry. Postulate 1-5 Ruler Postulate The distance between any two points is the absolute value of the difference of the corresponding numbers (on a number line or ruler) Congruent Segments : two segments with the same length.
Chapter 1 Tools of Geometry
The distance between any two points is the absolute value of the difference of the corresponding numbers (on a number line or ruler)
Congruent Segments: two segments with the same length
If three points A, B, and C are collinear and B is between A and C, then AB + BC = AC
If DT = 60, find the value of x. Then find DS and ST.
2x - 8
3x - 12
If EG = 100, find the value of x. Then find EF and FG.
4x - 20
2x + 30
B is the midpoint, so AB = BC
C is the midpoint of AB. Find AC, CB, and AB.
3x – 4
2x + 1
Z is the midpoint of XY, and XY = 27. Find XZ.
The endpoint is called the vertex
Can be named by the vertex, by three letters with the vertex in the center, or by a number
*Look at example 4 in the book, pg 27
You can use a protractor to measure an angle.
*Look in book on page 28
> 90° but < 180°
(90° < x < 180°)
*Example 5 on pg 28
If point B lies in the interior of <AOC, then m<AOB + m<BOC = m<AOC
If <AOC is a straight angle, then m<AOB + m<BOC = 180
What is m<TSW if m<RST = 50 and m<RSW = 125?
If m<DEG = 145, find m<GEF.
Congruent Angles: Angles with the same measure
Pg 29 1-28