| A | B |
|---|
| Point | an exact location or place |
| line | a straight path of points that goes on forever in two directions |
| ray | part of a line with one endpoint, extending forever in only one direction |
| line segment | part of a line with two endpoints |
| midpoint | the point halfway between two endpoints of a line segment |
| congruent lines segments | line segments with the same length |
| plane | a flat surface that extends forever in all directions |
| intersecting lines | two lines that cross through the same point |
| parallel lines | are in the same plane and will never intersect |
| perpendicular lines | are intersecting lines that form right angles |
| skew lines | line in different planes, never intersect and are not parallel |
| right angles | square corners |
| vertex/vertices | place where two lines form an angle |
| angle | formed by two rays that have the same endpoint |
| acute angle | between 0 and 90 degrees |
| right angle | exactly 90 degrees |
| obtuse angle | between 90 and 180 degrees |
| straight angle | exactly 180 degrees |
| protractor | used to measure and draw angles |
| adjacent angles | two angles with a common vertex and a common side |
