Section 3.2 Angle Measure

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Section 3.2 Angle Measure
Angles are measured in units called degrees
(O). In a full circle there are 360O. When
you measure an angle you measure how wide the
opening is between the rays, NOT THEIR
LENGTHS! To measure an angle or create an angle
with a specific measure we use a tool called a
protractor.
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Using a Protractor
Make a 40O angle.
To make an angle Make a ray using the straight
edge of your protractor Line up the protractor
with your ray like you were measuring an
angle. Make a point at the desired angle
measure Connect your ray's endpoint to your new
point using the straight edge of the protractor.
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Using a Protractor
To measure an angle Line up the center point on
the protractor with your vertex Line up the
bottom line on the protractor with a ray of the
angle See where the other ray intersects the
protractor.
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Types of Angles
Every angle can be classified as either right,
acute, obtuse, or straight.
Right Angle - a 90O angle. Acute Angle - an
angle smaller than 90O Obtuse Angle - an angle
bigger than 90O Straight Angle - a 180Oangle.