1. Angle Relationships in Parallel Lines and Triangles
Module 11

2. Review Solving two step equations
7x + 9 = The goal is to get the variable (x) ALONE!
Use reverse order of operations
7x + 9 = 30
____________
7x = 21
X =3

3. Naming Angles
You always names angles putting the vertex as the middle letter and use the angle symbol c a b
< abc or <cba

4. Do page 344

5. Angle Review Complementary Angles: Supplementary Angles:
Two angles whose measures add to 90˚
Supplementary Angles:
Two angles whose measures add to 180˚
22 ˚
48 ˚

6. Vocabulary Parallel lines: lines in a plane that do not intersect
Transversal: a line that intersects two lines in the same plane at two different points.

7. What do you know about these angles?
Vocab word:
Corresponding, alternate interior, same side interior, alternate exterior, same side exterior, & vertical
1 2 exterior interior 7 8 exterior

8. Angles
Vertical Angles: A pair of opposite congruent angles formed by intersecting lines
<1 and <4, <2 and <3, <6 and <7, <5 and < 8
Corresponding angles: lie on the same side of the transversal, on the same side of the parallel lines
<1 and <5, <2 and <6, <3 and <7, <4 and <8
Alternate interior angles: non adjacent angles that lie on opposite sides of the transversal between the parallel lines
<3 and <6, <4 and <5
Alternate Exterior Angles: lie on opposite sides of the transversal on the outside of the parallel lines.
<1 and <8, <2 and <7
Same Side Interior Angles: lie on the same side of the transversal, between the parallel lines
<3 and <5, <4 and <6

9. Angles
Congruent angles have the same angle measure and its identified by the following symbol~
Corresponding, vertical, and alternate interior and alternate exterior angles are congruent
So…
<1, <4, <5, <8 are congruent
<2, <3, <6, <7 are congruent

10. Angle Measures If <1 = 65˚ what is the measure of <4? Justify?
<4 is 65 ˚ <1 and <4 are congruent because they are vertical angles
What is the angle measure of <3? Justify?
<3 is 115˚ because <1 and <3 are supplementary angles. Since <1 is ˚ 65˚,subtract that from 180 ˚ and get 115˚
What is the angle measure of <8? Justify?
<8 is 65 ˚ because <1 and <8 are alternate exterior angles which are congruent.
Angle Measures

11. Solve for a b=6x˚ a =3x˚ Since <b + <a =180 ˚ 3x ˚ + 6x ˚ = 180
X =20
So 3x ˚ = 3(20) ˚ = 60 ˚

12. Page 350 #5-7 & Pg 351 #11-16