| A | B |
|---|
| Point | exact location in space |
| Line | straight and continues in opposite directions |
| Plane | flat and extends indefinitely |
| Parallel Lines | are in same plane but never intersect |
| Perpendicular Lines | lines intersecting at right angles |
| Line Segment or Segment | a part of a line with two endpoints |
| Ray | part of a line with one endpoint |
| Acute Angle | angle between 0 and 90 degrees |
| Right Angle | 90 degree angle |
| Obtuse Angle | angle between 90 and 180 degrees |
| Protractor | instrument used to measure angles |
| Supplementary Angles | Two angles whose measures add to 180 degrees |
| Complementary Angles | two angles whose measures add to 90 degrees |
| Adjacent Angles | two angles that share a common ray |
| Vertical Angles | congruent angles opposite one another |
| Corresponding Angles | congruent angles on the same side of the transversal |
| Congruent Angles | angles with the same measure |
| Interior Angles | angles between the parallel lines when cut by a transversal |
| Exterior Angles | angles outside of the parallel lines cut by a transversal |
| Transversal | a line that cuts through a pair of parallel lines |
