Download Angles and Geometry 9.10.15

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Angles and Geometry
9.10.15
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Do Now
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Define the following:
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Acute angle
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Straight angle
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Right angle
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Obtuse angle
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Ray
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Line
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Line segment
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How do you prove you are right?
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Proving You Are Right
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We write an explanation of our thinking or thought process
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An explanation should:
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Answer the question
Use key terms
Show what you know with strong and relevant
statements- “I know this because” “I think this
because”
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What type of angle do you think this is? Provide an
explanation of your thinking.
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I think this type of angle is an acute angle. I think this type of
angle is an acute angle because it measure 45 degrees and
to be an acute angle the angle must measure less than 90
degrees.
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What type of angle do you think this is? Provide an
explanation of your thinking.
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I think this type of angle is an acute angle. I think this type of
angle is an acute angle because it measure 72 degrees and
to be an acute angle the angle must measure less than 90
degrees.
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You try!
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What type of angle do you think this is? Provide an
explanation of your thinking.
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What type of angle do you think this is? Provide an
explanation of your thinking.
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I think this type of angle is a right angle. I think this type of
angle is a right angle because it measure 90 degrees and to
be a right angle the angle must measure exactly 90 degrees.
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What type of angle do you think this is? Provide an
explanation of your thinking.
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I think this type of angle is an obtuse angle. I think this type
of angle is an obtuse angle because it measures 120 degrees
which is more than 90 degrees and less than 180 degrees and
to be an obtuse angle the angle must measure more than 90
degrees and less than 180 degrees.
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What type of angle do you think this is? Provide an
explanation of your thinking.
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I think this type of angle is an obtuse angle. I think this type
of angle is an obtuse angle because it measures 135 degrees
which is more than 90 degrees and less than 180 degrees and
to be an obtuse angle the angle must measure more than 90
degrees and less than 180 degrees.
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What type of angle do you think this is? Provide an
explanation of your thinking.
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Practice
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Say what type of angle it is and provide an explanation to
support your thinking!
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Joe thinks the following angles are complementary? Is Joe
correct or incorrect? How do you know?
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Joe is correct. I know Joe is correct because in order to be
complementary angles the angles must be next to each
other, which they are, and have a sum of 90 degree. Since
58+32=90 degrees, I know the two angles are
complementary.
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Joe thinks the following angles are supplementary ? Is Joe
correct or incorrect? How do you know?
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Joe is correct. I know Joe is correct because in order to be
supplementary angles the angles must be next to each other,
which they are, and have a sum of 180 degrees. Since
139+41=180 degrees, I know the two angles are
supplementary.
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Joe thinks the following angles are complementary? Is Joe
correct or incorrect? How do you know?
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Joe is incorrect. I know Joe is incorrect because in order to be
complementary angles the angles must be next to each other,
and have a sum of 90 degree. Even though these two angles are
next to each other, their sum does not equal 90 degrees. Since
120+60=180 degrees, I know the two angles are supplementary
and not complementary. Also the two angles make a straight line
which also tells me they are supplementary.
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Joe thinks the following angles are supplementary? Is Joe
correct or incorrect? How do you know?
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Joe is incorrect. I know Joe is incorrect because in order to be
supplementary angles the angles must be next to each other,
and have a sum of 180 degree. Even though these two angles
are next to each other, their sum does not equal 180 degrees.
Since 25+65=90, I know the two angles are complementary
and not supplementary. Also, the two angles form a right
angles which also tells me the angles are complementary.
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Joe thinks the following angles are complementary? Is Joe
correct or incorrect? How do you know?
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Joe thinks the following angles are supplementary ? Is Joe
correct or incorrect? How do you know?
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Joe thinks the following angles are complementary? Is Joe
correct or incorrect? How do you know?
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Joe thinks the following angles are supplementary? Is Joe
correct or incorrect? How do you know?
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Practice
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What type of angle is below, how do you know?