1. Line and Angle Relationships Intro and Review

2. Acute angles are LESS than 90˚.

3. Right angles are EQUAL to 90˚.

4. Obtuse angles are BIGGER than 90˚.

5. Straight angles are 180˚.

6. Two Angles are complementary angles if they add up to 90˚.

7. FUN TRICK TO REMEMBER: “C” for Complementary… “C” makes 90!

8. If two angles are complementary and one of them is 77°, what is the size of the other angle?
13°

9. If two angles are complementary and one of them is 34°, what is the size of the other angle?
56°

10. Two Angles are supplementary angles if they add up to 180˚.

12. FUN TRICK TO REMEMBER: “S” for Supplementary… “S” makes 180!S

13. Two angles are supplementary and one of them is 31° What is the size of the other angle?
149°

14. Two angles are supplementary and one of them is 127° What is the size of the other angle?
53°

15. Vertical angles are angles OPPOSITE each other and formed by INTERSECTING lines. “Vertical” in this case means they share the same vertex (or corner point), not the usual meaning of up-down.

16. In this example, angles a and b are vertical angles
In this example, angles a and b are vertical angles. Vertical angles are ALWAYS CONGRUENT (EQUAL).

17. Two angles are adjacent angles if they have a common SLIDE, share a common VERTEX, and do not overlap.