1. Warm-up: Quiz your neighbor with your flash cards!!

2. Parallel Lines & Angles
To identify relationships between figures in space
To identify angles formed by two lines and a transversal

3. Parallel lines
Coplanar lines that do NOT intersect. The symbol || means “is parallel to.”
Ex.

4. Transversal--A line that intersects two or more lines.

5. Alternate Interior Angles--Angles
on opposite sides of a transversal and inside two other lines 1 2 8 3 7 4 6 5
Remember: make a zee…..
Alternate Interior Angles Theorem- If a transversal intersects two parallel lines, then alternate interior angles are congruent.

6. Corresponding Angles-Angles in the same position relative to a transversal and two other lines1 2 8 3 7 4 6 5
Corresponding Angles Postulate – If a transversal intersects two parallel lines, then corresponding angles are congruent.

7. Consecutive Interior-Angles on the same side of a transversal and inside two other lines1 2 8 3 7 4 6
Remember…makes a C. 5
Consecutive Interior Angles Theorem – If a transversal intersects two parallel lines, then same-side interior angles are supplementary.

8. Alternate Exterior Angles-Angles on opposite sides of a transversal and outside two other lines1 2 8 3 7 4 6 5
Alternate Exterior Angles Theorem – If a transversal intersects two parallel lines, then alternate exterior angles are congruent.

9. What tells us that m3 + m2 = 180?
In the diagram above, l || m. Find m1 and then m2.
State your reasoning.

10. In the diagram below, a || b, find all the angles that are equal in measure to 3.1 2 6 3 5 4 7 8 a b

11. In the diagram above, l || m. Find the values of a, b, and c.