This geometry worksheet challenges students to calculate missing angles using properties of parallel lines and transversals, requiring them to justify their answers.

1. 70°, Vertical angles are congruent.
2. 110°, Supplementary angles sum to 180°.
3. 70°, Vertical angles are congruent.
4. 110°, Supplementary angles sum to 180°.
5. 60°, Vertical angles are congruent.
6. 120°, Supplementary angles sum to 180°.
7. 60°, Vertical angles are congruent.
8. 120°, Supplementary angles sum to 180°.
9. 90°, Perpendicular lines form right angles.
10. 90°, Perpendicular lines form right angles.
11. 90°, Perpendicular lines form right angles.
12. 90°, Perpendicular lines form right angles.
13. 50°, Alternate interior angles are congruent when lines are parallel.
14. 130°, Same-side interior angles are supplementary when lines are parallel.
15. 50°, Corresponding angles are congruent when lines are parallel.
16. 130°, Alternate exterior angles are congruent when lines are parallel.
17. 40°, Alternate interior angles are congruent when lines are parallel.
18. 140°, Same-side interior angles are supplementary when lines are parallel.
19. 40°, Corresponding angles are congruent when lines are parallel.
20. 140°, Alternate exterior angles are congruent when lines are parallel.