| A | B |
|---|
| collinear points | (points) on the same line |
| noncollinear points | (points) not on the same line |
| point | represented by a "dot", no actual size, named with a capital letter |
| line | extends forever in 2 directions, straight, no thickness, determined by 2 points |
| plane | a flat surface that extends forever, has no thickness, determined by 3 noncollinear points |
| coplanar | on the same plane |
| noncoplanar | not on the same plane |
| intersection of two lines is a ... | point |
| segment addition postulate | If B is between A and C, then AB + BC = AC |
| midpoint definition | If M is the midpoint of AB, then AM = MB |
| congruent figures | figures that have the same size and shape |
| congrent segments | segments that are equal in length |
| segment bisector | a segment, line or plane that intersects a segment at its midpoint |
| Number of noncollinear points that define a plane | 3 |
| Number of points that define a line | 2 |
| How many planes can contain 3 collinear points? | Infinitely many |
| Two planes intersect in a ... | Line |
| Ray | has one endpoint, extends infinitely in one direction |
| opposite rays | 2 rays that share the same endpoint and form a line |
| angle | a figure formed by 2 rays that have the same endpoint |
| straight angle | an angle whose measure is 180° |
