| A | B |
| congruent | angles that are equal |
| acute | angles that are LESS than 90 degrees |
| obtuse | angles that are MORE than 90 degrees |
| complementary | angles that add up to 90 degrees |
| supplementary | angles that add up to 180 degrees |
| vertical | angles that are OPPOSITE each other and congruent |
| right | an angle that EQUALS 90 degrees |
| straight | an angle that EQUALS 180 degrees |