## Wirtz Combined Geometry Chapter 1 Lesson 3

Term Definition
segment of a line (p11) Two points on the line and all points between them.
ray (p11) A portion of a line which starts at a point and goes off in a particular direction to infinity.
opposite rays (p11) Two rays with a common endpoint that point in opposite directions and form a straight line.
length of a segment (p11) The distance between its endpoints
postulates (p12) A statement that is accepted without proof.
axioms (p12) A statement that is accepted without proof.
congruent segments (p13) Segments that have equal lengths.
midpoint of a segment (p13) The point that divides the segment into two congruent segments.
bisector of a segment (p13) A line, segment, ray, or plane that intersects the segment at its midpoint.
number line (p11) A line on which numbers are marked at intervals, used to illustrate simple numerical operations.
coordinate (p11) Each of a group of numbers used to indicate the position of a point, line, or plane.
congruent (p13) When two objects have the same size and same shape.
Segment Addition Postulate (p12) If B is between A and C, then AB + BC = AC.