| A | B |
|---|
| right angle | 90˚ |
| acute angle | angle less than 90˚ |
| collinear | points on the same line |
| obtuse angle | angle more than 90˚but less than 180˚ |
| point | where two lines intersect |
| parallel | lines that go in the same direction and don't meet |
| skew | lines that are on different planes |
| protractor | tool to measure angles |
| complementary | two angles that add up to 90˚ |
| supplementary | two angles that add up to 180˚ |
| vertical angles | angles opposite each other when lines intersect |
