| A | B |
|---|
| conjecture | an unproven statement based on a pattern |
| vertex | the endpoint of the rays that form an angle |
| coplanar lines | lines on the same plane |
| straight angle | angle that measures 180 degrees |
| congruent | having the same length or measure |
| counter-example | example that shows a conjecture is false |
| obtuse angle | angle that has a measure greater than 90 degrees but less than 180 degrees |
| collinear points | points on the same line |
| sides of an angle | the rays that make up the angle |
| coordinate | the real number that corresponds to a point |
