MJ3

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MJ3

• Ch 6.1 Line Angle Relationships

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1. In art class Mark mixed 3 liters of yellow
paint, 2 liters of red paint and 1 liter of blue
paint. How many milliliters of paint did Mark mix
in the bucket?
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6
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0
(1 liter 1000 milliliters)
6 liters 6000 milliliters
Bellwork You do not have to write the question!
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Assignment Review

• None

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Before we begin.

• Please take out your notebook and get ready to
  work
• Today we will look at angles from a different
  perspectiveThat is angles formed by 2 parallel
  lines cut by a transversal.
• Before we do that we need to make sure everyone
  understands the vocabulary used when talking
  about lines and angle relationships

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Objective

• Students will identify line and angle
  relationships

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Vocabulary

• Acute Angles have a measure less than 90
• Right Angles have a measure equal to 90
• Obtuse Angles have a measure greater than 90
• Straight Angles have a measure of 180

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Vocabulary

• Parallel lines Two lines on a plane that never
  intersect.
• Transversal A line that intersects 2 parallel
  lines and creates 8 angles.
• Interior angles lie inside the parallel lines
• Exterior angles lie outside the parallel lines
• Alternate interior angles are on opposite sides
  of the transversal and inside the parallel lines
• Alternate exterior angles are on opposite sides
  of the transversal and outside the parallel
  lines.
• Corresponding angles are in the same position on
  the parallel lines in relation to the transversal

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Properties

• If two parallel lines are cut by a transversal,
  then the following pairs of angles are congruent.
• Corresponding angles are congruent
• Alternate interior angles are congruent
• Alternate exterior angles are congruent
• Lets look at an example

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Parallel Lines Cut by a Transversal
a
b
c
d
e
f
g
h
? a 110
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Your Turn

• In the notes section of your notebook draw two
  parallel lines cut by a transversal. Then find
  an acute angle and give it the measure of 60.
  Then find the measure of the remaining angles.

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• More Lines Angle Relationships

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Intersecting Lines and Angles

• Vertical Angles Angles formed by two
  intersecting lines. Vertical angles are
  congruent
• Example

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1
3
2
Angles 1 3 are vertical angles Angles 2 4 are
vertical angles
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Adjacent Angles

• When two angles have the same vertex, share a
  common side, and do not overlap they are adjacent
  angles
• Example

Angle 1 2 are adjacent angles The m?AOB m?1
m?2
A
1
2
B
O
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Complimentary Angles

• If the sum of the measures of two angles equal
  90, the angles are complimentary
• Example

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3
1
2
You may see complimentary angles displayed 2 ways
as pictured above. If the measures of the angles
equal 90, then they are complimentary
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Supplementary Angles

• If the sum of two angles equals 180, then the
  angles are supplementary
• Example

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4
You may see supplementary angles displayed 2 ways
as pictured above. If the measures of the angles
equal 180, then they are supplementary
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Finding the Missing Measure

• You can find the missing measure of a pair of
  angles by classifying the angles then subtract
  the given measurement from the total measurement.
• Example
• You can find the value of x by classifying
• the angles as supplementary and 180
• Then subtract 118 from 180
• to get the value of x 62

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Summary

• In the notes section of your notebook summarize
  the key concepts covered in todays lesson
• Today we discussed
• Parallel lines cut by a transversal
• Vertical angles
• Complimentary angles
• Supplementary angles

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Assignment

• Practice skills workbook Lesson 6.1
• Reminder
• This assignment is due tomorrow.
• I do not accept late assignments