1. Angles Formed by Parallel Lines and Transversals
Module 3-1 Notes
Angles Formed by Parallel Lines & Transversals
Monday August 26th
Holt McDougal Geometry
Holt Geometry

2. Warm Up 1) If 2 angles add up to 900, then they are complementary
CONVERSE
INVERSE
CONTRAPOSITIVE
2) What value of y makes the 2 figures similar?
If 2 angles are complementary, then they add up to 900
If 2 angles don’t add up to 900, then they aren’t complementary
If 2 angles aren’t complementary, then they don’t add up to 900

3. Vocabulary
Transversal – A line that intersects 2 coplanar lines at 2 different points
Parallel Lines – lines in the same plane that do NOT intersect

4. 1 2 3 4 5 6 7 8 5 1 6 2 7 3 8 4

6. Example 1: Using the Corresponding Angles Postulate
Find each angle measure.
A. mECF
B. mDCE

7. Try this on your own…
Find mQRS.

8. Alternate Interior Angles Alternate Exterior Angles Same-Side Interior Angles 5 1 6 2 7 3 8 4

9. Example 2: Finding Angle Measures
Find each angle measure.
A. mEDG
B. mBDG

10. Try this on your own…
Find mABD.
Alt. Interior Angles

11. Classwork
m JKL = m BEF = 630
m 1 = m CBY = 660