| A | B |
|---|
| point | an exact location |
| line | a neverending straight path |
| line segment | 2 endpoints and the straight path between them |
| ray | a neverending straight path in only one direction |
| plane | a neverending flat surface |
| triangle | a 3 sided polygon |
| quadrilateral | a 4 sided polygon |
| pentagon | a 5 sided polygon |
| hexagon | a 6 sided polygon |
| heptagon | a 7 sided polygon |
| octagon | an 8 sided polygon |
| nonagon | a 9 sided polygon |
| decagon | a 10 sided polygon |
| angle | 2 rays with a common endpoint |
| acute angle | measures less than 90 degrees |
| right angle | measures 90 degrees |
| obtuse angle | measures between 90 and 180 degrees |
| straight angle | measures 180 degrees |
| reflex angle | measures between 180 and 360 degrees |
| vertical angles | opposite angles when 2 lines intersect |
| complementary angles | 2 angles whose sum is 90 degrees |
| supplementary angles | 2 angles whose sum is 180 degrees |
| adjacent angles | 2 angles that share a common ray |
| perpendicular lines | 2 lines that intersect to form 90 degree angles |
| intersecting lines | 2 lines that cross |
| parallel lines | 2 lines that do not intersect |
| skew lines | 2 lines that do not intersect but are not parallel |
