| A | B |
|---|
| Parallel Lines | Lines in the same plane that never intersect |
| Perpendicular Lines | Two lines that intersect at right angles |
| Intersecting Lines (but NOT perpendicular) | Lines that have exactly one point in common |
| Line | An endless collection of points in a straight path with no endpoints |
| Line Segment | A part of a line having two endpoints |
| Ray | A part of a line with one endpoint and goes on in one direction |
| Vertex of an angle | Point of intersection of two rays when forming an angle |
| Acute Angle | Angle measuring less than 90 degrees |
| Right Angle | Angle measuring 90 degrees |
| Obtuse Angle | Angle measuring greater than 90 degrees |
| Straight Angle | Angle measuring 180 degrees |
