1. Warm Up
Complete the handout and turn in when finished

2. Practice with Supplemental Angles
Find the missing Angle: Find x:

3. Let’s look at a pair of parallel lines cut by a transversal.
What kind of angles are 1 and 2?
Corresponding
If we TRANSLATE the bottom line upward, what do we notice? 1
Ask what translate means! It’s the same angles 2

4. Properties of Parallel Lines

5. Let’s look further… Suppose mb = 60
Use what you know about vertical, supplementary, and corresponding angles to find the measures of all the other angles
Can we make any conclusions?

6. More Postulates
When a transversal intersects two parallel lines, we have two other interesting angle properties

7. II.
This is easy to remember because we know about vertical angles and corresponding angles!

8. III.
This is easy because we know supp (linear pair) and corr

9. Two options for angles with parallel lines and transversals
Either the two angles are congruent
(Vertical angles, Alternate, Corresponding)
or they add to 180
(same side interior, same side exterior, create straight line)

10. Find x

11. Create equations and solve

14. Group Work
Use the properties of parallel lines cut by a transversal to determine the indicated angles.
lines.html

15. More Definitions
Bisect – to divide a line/angle/shape into two equal parts
Perpendicular Bisector - A line which cuts a line segment into two equal parts at a right angle (90°).

16. Homework
Set up equations using the properties of parallel lines cut by a transversal to solve.