lesson 10-1 pages 492-497

Lesson 10-1 Pages 492-497

Line and Angle Relationships

Lesson Check Ch-9

What you will learn!1. How to identify the relationships

of angles formed by two parallel lines and a transversal.

2. How to identify the relationships of vertical, adjacent, complementary, and supplementary angles.

Parallel linesParallel lines Corresponding anglesCorresponding angles

TransversalTransversal Vertical anglesVertical angles

Interior anglesInterior angles Adjacent anglesAdjacent angles

Exterior anglesExterior angles Complementary anglesComplementary angles

Alternate interior anglesAlternate interior angles Supplementary anglesSupplementary angles

Alternate exterior anglesAlternate exterior angles Perpendicular linesPerpendicular lines

What you really need to know!

When two parallel lines are intersected by a third line called a transversal, eight angles are formed!

What you really need to know!

Interior angles lie inside the parallel lines!

3, 4, 5, 6

What you really need to know!

Exterior angles lie outside the parallel lines!

1, 2, 7, 8

What you really need to know!Alternate interior angles are on opposite sides of the transversal and inside the parallel lines!

3 and 5,

4 and 6

What you really need to know!Alternate exterior angles are on opposite sides of the transversal and outside the parallel lines!

1 and 7,

2 and 8

What you really need to know!Corresponding angles are in the same positions on the parallel lines in relation to the transversal!

1 and 5,

4 and 8,

2 and 6,

3 and 7

What you really need to know!

Example 1:

In the drawing, m ║ n and t is a transversal. If m 7 = 123°, find m 2 and m 8.

Example 1:

m 2 = 57°

and

m 8 = 57°

Example 2:

If m D = 53° and D and E are complementary, what is m E?

AA BB CC DD

5353°° 3737°° 127127°° 77°°

AA BB CC DD

5353°° 3737°° 127127°° 77°°

Example 3:

Angles PQR and STU are supplementary. If m PQR = x – 15 and m STU = x – 65, find the measure of each angle.

(x – 15) + (x – 65) = 180

2x – 80 = 180

2x = 260

x = 130

m PQR = 130 – 15 = 115°

m STU = 130 – 65 = 65°

Example 4:

A road crosses railroad tracks at an angle as shown. If m1 = 131°, find the m6, and m5.

m6 = 49°

and

m5 = 131°

Page 495

Guided Practice

#’s 3-9

Pages 492-495 with someone at home and

study examples!

Read:

Homework: Pages 496-497

#’s 10-31 all

#’s 35-36, 43-45

Lesson Check 10-1

Page

747

Lesson 10-1

Lesson Check 10-1