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Making 2-rays angles from rotation angles

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There are two main ideas of what an angle is:

a) the amount of opening between two rays

b) the amount of a rotation

This applet shows how to get a 2-rays angle from a rotation:

  • Use the center of the rotation (O) as the vertex of the angle.
  • Pick a point on the object that is rotation, such as A.
  • Call A' the rotation of A.
  • Draw angle AOA'.

Susan Addington, Created with GeoGebra

Updated May 15, 2010


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