Vocabulary and Postulates for 1-3

1.  Coordinates of a Point – the distance and direction from
the origin of a number line. The coordinates of a point
are in the form (x,y), where x is the x-coordinate and y is
the y-coordinate.
 Distance Between two points on a line – the absolute
value of the difference of the coordinates of the points
 Congruent Segments – segments that have the same
length
 Midpoint of a segment – the point that divides the
segments into two congruent segments
 Segment bisector – a line, segment, ray or plane that
intersects a segment at its midpoint.
SECTION 1-3 VOCABULARY

2.  Postulate 1-5 Ruler Postulate
Every point on a line can be paired with a real number.
This makes a one-to-one correspondence between the
points on the line and the real numbers. The real
number that corresponds to a point is called the
coordinate of the point.
SECTION 1-3 POSTULATES

3.  Postulate 1-6: Segment Addition Postulate
If three points A, B and C are collinear and B is
between A and C, then AB + BC = AC.
SECTION 1-3 POSTULATES