Classify each angle as acute, obtuse, right or straight

1
Classify each angle as acute, obtuse, right or
straight
2
Angles, Angles Everywhere
3
Where do you see angles?
4

• An angle is formed by two rays with a common
  endpoint called the vertex.

vertex
vertex
vertex
5
An angle can be named by its vertex or by its
vertex and a point form each ray.
Angle C or Angle BCR or Angle RCB
B
R
C
6
Classifying angles

• You can classify an angle by its measure.

Acute measures less than 90
Right measures 90
Obtuse measures greater than 90 but
less than 180
Straight measures 180
7
Using a protractor

• Place the center point of the protractor on the
  vertex of the angle.
• Place the protractor so that ray YZ passes
  through the 0 mark.
• Using the scale that starts with 0 along ray YZ
  and the measure where ray YX crosses.
• The measure of Angle XYZ is .

X
Z
Y
8
Websites

• http//www.amblesideprimary.com/ambleweb/mentalmat
  hs/protractor.html