| __ | 6. | Acute angle | | A. | Angle whose measure is less than 90 degrees |
| __ | 7. | Adjacent angles | | B. | Lines that form a right angle |
| __ | 8. | Complementary angles | | C. | Angle whose measure is 180 degrees |
| __ | 9. | Degree | | D. | Angles with same vertex and sides formed by the same lines |
| __ | 10. | Obtuse angle | | E. | Angle whose measure if 90 degrees |
| __ | 11. | Perpendicular lines | | F. | Unit of measure used for angles |
| __ | 12. | Right angle | | G. | Two angles whose measure adds to be 180 degrees |
| __ | 13. | Straight angle | | H. | Angle whose measure is greater than 90, less than 180 |
| __ | 14. | Supplementary angles | | I. | Two angles whose measure adds to be 90 degrees |
| __ | 15. | Vertical angles | | J. | Angles with same vertex and one common side |