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Page |
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Math
A |
Types
of Angles |
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An
angle
is the intersection of two rays with a
common endpoint.
It may look like any of the following:
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Types
of Angles |
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Acute
- any angle which measures less
than 900
Right
- any angle which measures
exactly
900.
| Obtuse
- |
any
angle which measures more
than 900, but
less than 1800
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Straight -
any angle which measures exactly
1800.
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Pairs of
Angles |
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The definitions above apply to angles when we look at one angle alone,
but
there are also some special relationships between pairs of angles.
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Adjacent Angles |
-
2 angles which share a vertex,
share a side, but
do not
overlap.
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Angle 1 and
angle 2 are
adjacent angles.
Angle 1 and angle ABC are
NOT
adjacent. |
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Vertical Angles |
- 2 angles formed by
intersecting lines.
They can
not
be adjacent, and they are always equal in measure. They are across
from one another in the corners of the "X" formed by the lines. |
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Angle 1 and angle
3 are
vertical angles.
Angle 2 and angle 4 are
vertical angles.
Angle 1 and angle 2 are
not vertical. |
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Complementary
Angles |
- 2 angles
whose measures add up to 900.
Complementary angles can be placed
so that they form perpendicular lines. |
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Angle 1 and angle 2 are
complementary.
Angle XYZ and angle 1 are
not
complementary.
Line segment XY is
perpendicular to line
segment YZ. |
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Supplementary
Angles |
-
2 angles whose measures add up to 1800.
Supplementary angles can be
placed so that they form a straight line.
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Angle 1 and angle
2 are
supplementary.
The line passing through points
A, B, and C is a straight line.
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