1. 3-2: Angles Formed by Parallel Lines and Transversals
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3-2: Angles Formed by Parallel Lines and Transversals

2. Page 148 (Answers may vary)
14)
𝐴𝐵 ∥ 𝐷𝐸
15)
𝐴𝐵 & 𝐶𝐹 are skewed
16)
𝐵𝐷 ⊥ 𝐷𝐹
17)
Plane ABC || Plane DEF
18)
∠2 & ∠6
19)
∠1 & ∠8
20)
∠1 & ∠6
21)
∠2 & ∠5
22)
Transversal: p; Correspond.
23)
Transversal: q; Alt. Int. Ang.
24)
Transversal: l; Alt. Ext. Ang.
25)
Transversal: p; Same-Side Int.
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3-2: Angles Formed by Parallel Lines and Transversals

3. 3-2: Angles Formed by Parallel Lines and Transversals
1/15/2019 5:31 PM
3-2: Angles Formed by Parallel Lines and Transversals

4. Angles Formed by Parallel Lines and Transversals
Section 3–2
Geometry PreAP, Revised ©2013
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3-2: Angles Formed by Parallel Lines and Transversals

5. 3-2: Angles Formed by Parallel Lines and Transversals
Postulate and Theorem
Postulate/Axiom: Describes a fundamental relationship between the basic terms of geometry: Accepted to be true without proof
Theorem: A statement or conjecture that can be proven true by undefined terms, definitions and postulates.
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3-2: Angles Formed by Parallel Lines and Transversals

6. Postulates Type of Theorem/Postulate Definition Visual Example
A) Corresponding Angles Postulate
If two parallel lines are cut by a transversal, then pairs of corresponding angles are congruent.
B) Alternate Interior Angles Theorem
If two parallel lines are cut by a transversal, then pairs of alternate interior angles are congruent.
C) Alternate Exterior Angle Theorem
If two parallel lines are cut by a transversal, then pairs of alternate exterior angles are congruent.
D) Consecutive Interior Angles Theorem
If two parallel lines are cut by a transversal, then pairs of consecutive interior angles are supplementary.
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3-2: Angles Formed by Parallel Lines and Transversals

7. 3-2: Angles Formed by Parallel Lines and Transversals
Example 1
On the map below, 1st and 2nd Ave. are parallel. A city planner on the triangular island is formed by the intersections of the four streets below. What are the measures of the angles of the garden and park?
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3-2: Angles Formed by Parallel Lines and Transversals

8. 3-2: Angles Formed by Parallel Lines and Transversals
Example 2
Using the diagram below, solve for 𝑚∠𝐸𝐶𝐹 and 𝑚∠𝐷𝐶𝐸
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3-2: Angles Formed by Parallel Lines and Transversals

9. 3-2: Angles Formed by Parallel Lines and Transversals
Example 3
Using the diagram below, solve for 𝑚∠𝐸𝐷𝐺 and 𝑚∠𝐵𝐷𝐺
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3-2: Angles Formed by Parallel Lines and Transversals

10. 3-2: Angles Formed by Parallel Lines and Transversals
Example 4
Using the diagram below, solve for 𝑚∠𝐸𝐷𝐺 and 𝑚∠𝐵𝐷𝐺
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3-2: Angles Formed by Parallel Lines and Transversals

11. 3-2: Angles Formed by Parallel Lines and Transversals
Your Turn
Using the diagram below, if 𝑚∠5=2𝑥−10, 𝑚∠6=4 𝑦−25 and 𝑚∠7=𝑥+15, solve for x and y.
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3-2: Angles Formed by Parallel Lines and Transversals

12. 3-2: Angles Formed by Parallel Lines and Transversals
Example 5
What is the measure of 𝑚∠𝐺𝐻𝐼.
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3-2: Angles Formed by Parallel Lines and Transversals

13. 3-2: Angles Formed by Parallel Lines and Transversals
Your Turn
What is the measure of 𝑚∠𝐺𝐻𝐼.
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3-2: Angles Formed by Parallel Lines and Transversals

14. 3-2: Angles Formed by Parallel Lines and Transversals
Assignment
Page odd (omit 25), 28, 31, 37
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3-2: Angles Formed by Parallel Lines and Transversals