| A | B |
|---|
| line | a set of points that extend forever in opposite directions |
| line segment | the part of a line between two endpoints |
| ray | part of a line that starts at an endpoint and goes on forever in one direction |
| intersecting lines | lines that meet at a common point |
| parallel lines | lines on aflat surface that never intersect |
| perpendicular lines | lines that intersect at square corners |
| right angle | forms a square corner |
| acute angle | less than a right angle |
| obtuse angle | greater than a right angle |
| polygons | any closed flat figure with straight lines |
| parallelogram | opposite sides are parallel and equal |
| quadrilateral | any ploygon with 4 straight sides |
| congruent | same size, same shape-one can be moved to fit exactly over the other |
| similar | have same shape but not same size |
| symmetry | figure can be folded so two parts match |
| transformation | turn or rotation |
| slide or translation | a move in a straight line without changing direction |
| flip or reflection | move over imaginary line;puts objects in opposite directions |
