2. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Objective

3. 1 2 10/29 Lesson 3.2 What is the name of the angle pair, angles 1 and 2?

4. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals 1 2 What if the lines are parallel?

5. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Postulate or Theorem Name What it saysKey WordsPicture If 2 parallel lines are cut by a transversal, then… Corresponding Angles Postulate …the corresponding angles are congruent. Parallel lines Transversal Corresponding angles

6. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Find mQRS.

7. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals m n 1 2 34 5 7 6 8 If m<8 = 61˚, find the measures of all other numbered angles. Example 1)

8. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals m n 1 2 34 5 7 6 8 Alternate Interior angles are ____________. Alternate exterior angles are ____________. Same-side interior angles are ____________. Example 2)

9. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Alternate Interior Angles Theorem …the alternate interior angles are congruent. Parallel lines Transversal Alternate interior angles Alternate Exterior Angles Theorem …the alternate exterior angles are congruent. Parallel lines Transversal Alternate exterior angles Same-side Interior Angles Theorem …the same-side interior angles are supplementary. Parallel lines Transversal Same-side interior angles Supplementary

10. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Find each angle measure. A. mDCE B. mCBG

11. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Given m3 = 3x-1 and m5 = x+5. Find m1. Example 3)

12. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Given m3 = 2(x-35) and m4 = x+15. Find m5. Example 4)

13. Holt Geometry 3-2 Angles Formed by Parallel Lines and Transversals Objective

15. Exit Slip! 1.Let m1 = 120°, m2 = (60x)°. a. Give the name of the angle pair that describes <1 and <2. b. Write and solve an equation to find the measures of the angles. c. Name the theorem or postulate that justifies your solution. 2.Find m3 and m5 if m3 = (45x + 30)° and m5 = (25x + 10)°.