segment

a part of a line consisting of two points and all points in between them

endpoint

a point at one end of a segment or the starting point of a ray.

ray

a part of a line that starts at an endpoint and extends forever in one direction

opposite rays

two rays that have a common endpoint and form a line

postulate

or axiom; a statement that is accepted without proof.

coordinate

a point that corresponds to one and only one number on the ruler

distance

the absolute value of the difference of the coordinates

length

distance between A and B

congruent statements

segments that have the same length

construction

a way of creating a figure that is more precise

midpoint

the point that bisects the segment into two congruent statements

bisect

divide evenly

segment bisector

any ray, segment, or line that intersects a segment at its midpoint

angle

a figure formed by two rays, or sides, with a common endpoint called the vertex

vertex

a common endpoint

interior of an angle

the set of all points between the sides of the angle

exterior of an angle

the set of all points outside the angle