Download Chapter 3 Terms

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Geometry Concepts
Chapter 3 Terms
Term
Naming angles
Vertex of an angle
Interior of an angle
Exterior of an angle
Acute angle
Obtuse Angle
Right Angle
Straight angle
Angle bisector
Adjacent angles
Linear pairs
Complementary angles
Supplementary angles
Vertical angles
Perpendicular lines
Definition
Example
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How to find the measure of an ANGLE with a protractor:
Steps:
1. Put the vertex in the middle of
the line on the bottom of the
protractor.
2. Decide whether it is an acute or
obtuse angle.
3. Choose the larger number for
obtuse angles and the smaller
number for acute angles.
4. Name the angle with the vertex in
the middle of three letters.
5. Write = the number of degrees
with a  symbol.
How to find a missing angle in a diagram:
Steps:
1. If the angle is made up of two or
more parts that you know, then
add them together.
2. If the angle is part of a bigger
angle, then subtract the other
smaller angle(s) from the bigger
angle.
3. If a line bisects an angle, then
the smaller angle is half of the
bigger angle.
4. If the angles form a right angle,
then make the big angle 90.
5. If the angles form a linear pair or
straight angle, then make the big
angle 180
6. If the angles are vertical angles,
then they are equal to each other.