11 terms

postulate

(axiom) statement that is accepted as true without proof

midpoint

point that bisects the segment into two congruent segments

angle bisector

a ray that divides an angle into two congruent angles

undefined term

points, lines, planes (can't be defined by any figure)

angle

figure formed by two rays with a common endpoint

ray

starts at an endpoint and extends forever in one direction

segment

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

vertical angles

two nonadjacent angles formed by two intersecting lines

congruent angles

angles that have the same measure

opposite rays

two rays that have a common endpoint and form a line

segment bisectors

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