1.3: Angles - Angles and Rays

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1.3 Angles- Angles and Rays
GSE
M(GM)102 Makes and defends conjectures,
constructs geometric arguments, uses geometric
properties, or uses theorems to solve problems
involving angles, lines
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Rays

• A ray extends forever in one direction
• Has one endpoint
• The endpoint is used first when naming the ray

B
B
B
B
R
R
R
R
R
T
W
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Angles

• Angles are formed by 2 non-collinear rays
• The sides of the angle are the two rays
• The vertex is where the two rays meet

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Angles (cont.)

• Measured in degrees
• Congruent angles have the same measure

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Naming an Angle

• You can name an angle by specifying three points
  two on the rays and one at the vertex.
• The angle below may be specified as angle ABC or
  ABC. The vertex point is always given in the
  middle.

Vertex
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Ex. of naming an angle

• Name the vertex and sides of 4, and give all
  possible names for 4.

T
Vertex Sides Names
4 5
W X Z
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Name the angle shown as
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Angles can be classified by their measures

• Right Angles
• Acute Angles
• Obtuse Angles

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assignments