| A | B |
|---|
| parallel lines | never intersect |
| perpendicular lines | intersect forming right angles |
| congruent angles | same measure |
| acute angle | measures less than 90 degrees |
| obtuse angle | measures more than 90 degrees |
| right angle | measures 90 degrees |
| equilateral triangle | all 3 sides are congruent |
| isosceles triangle | 2 sides are congruent |
| scalene triangle | no sides are congruent |
| line | extends endlessly in both directions |
| line segment | a part of a line having 2 endpoints |
| ray | a part of a line extending endlessly in one direction |
| vertex | the endpoint of 2 rays forming an angle |
