14 terms

Geometry Grades 6-8 by Tiffany Moore and Jenae Hawkins pages 5-14

opposite rays

Two rays that share an endpoint and extend in opposite directions to form a line

point

Position in space, often represented by a dot

ray

A portion of a line that extends from one endpoint infinitely in one direction

point of intersection

The point at which two lines intersect

linear

Something that relates to or resembles a line

midpoint

A point that bisects a line segment

parallel lines

Lines in the same plane that never intersect

collinear points

Three or more points that lie in the same line

perpendicular lines

Two lines that form a right angle at their point of intersection

line segment

A finite portion of a line that has two endpoints

line

A set of points in a straight path that extends infinitely in both directions

plane

A flat surface that extends infinitely in all directions

coplanar points

Three or more points that lie in the same plane

flat-plane rule

If three points are coplanar, then the line containing two of the points is in the same plane