## Making 2-rays angles from rotation angles
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 |