Math geometry terms

point

has no length, width, or thickness. Only has position. Represented by a dot and named by a capital letter

line (def)

an infinite set of points, infinite length, having no width or thickness. named by any 2 points on it

line (axioms)

2 points determine a line, the intersection of lines is a point

collinear points

points on the same line

plane (def)

infinite flat surface consisting of an infinite set of points

plane (axioms)

3 noncollinear points determine a plane, the intersection of 2 planes is a line, if 2 points are in a plane then the line containing them is also in the plane

line segment

a set of points consisting of 2 points on a line called endpoints and all points on the line between these endpoints, has a finite length

length of a line segment

a positive number representing length or distance between 2 points

congruent segments

2 segments are congruent if and only if they have the same length

ray

part of a line consisting of one endpoint and all points of the line on one side of the endpoint

opposite rays

2 rays of the same line with a common endpoint and no other points in common