| A | B |
|---|
| collinear | (points) on the same line |
| noncollinear | (points) not on the same line |
| point | undefined term - represented by a "dot", no actual size, named with a capital letter |
| line | undefined term, extends forever in 2 directions, straight, no thickness, determined by 2 points |
| plane | undefined term, 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 figures | the set of points that are in both figures |
| the segment addition postulate | If B is between A and C as a picture: A-----B----C, then AB + BC = AC |
| midpoint | If A-------M---------B where M is the midpoint, 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 |
| How many points determine a plane? | 3 |
| How many points determine a line? | 2 |
| Does a plane have edges? | No |
| How many planes can contain 3 collinear points? | Infinitely many |
| Do two planes always intersect? | No |
| How many lines can pass through one point? | Infinitely many |
| Ray | half a line |
| 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 degrees |
| right angle | an angle whose measure is 90 degrees |
| obtuse angle | an angle whose measure is between 90 and 180 degrees |
| acute angle | an angle whose measure is between 0 and 90 degrees |
| angle bisector | a ray that divides an angle into two congruent angles |
| Every angle has ___ angle bisector | one |
| every segment has _____ segment bisectors | infinitely many |
| every segment has ______ midpoint | one |
| congruent angles | angles with equal measures |
| adjacent angles | angles in the same plane that have a common vertex and a common side but no common interior points |
| vertical angles | 2 nonadjacent angles formed by 2 intersecting lines |
| linear pair | 2 adjacent angles whose noncommon side form a straight line |
| Thm: vertical angles are _____ | congruent |
| supplementary angles | 2 angles whose measures add to 180 |
| complementary angles | 2 angles whose measures add to 90 |
| if 2 angles are a linear pair, then they are also ____ and ____ | adjacent and supplementary |
| perpendicular lines | two lines that intersect and form a right angle |
| If two angles for a linear pair, then they add to ____ | 180 |
