Defined Terms

bisector of a segment

a line or segment that intersects the segment at its midpoint

collinear points

a set of 2 or more points all on the same line

coplanar points

a set of 2 or more points on the same plane

length of a segment

distance between endpoints of a segment

betweenness of points

point b is between points a and c if a, b, and c are collinear and the equation ab + bc = ac is true, where ab, bc, and ac are the distances between points a and b, b and c, and a and c, respectively

midpoint of a segment

point on a segment that divides segment into two equal segments

opposite rays

ray ba and ray bc are opposite rays if a, b, and c are collinear and b (endpoint of both rays) is between a and c

ray

set of points beginning at point a and going infinitely in the direction of point b

line segment

set of two different endpoints and all points between them

space

the set of all possible points