Creates an arc by defining the start point, a point on the arc, and the endpoint. This is a "generic" arc tool, because the local menu options enable you to define the arc in a number of different ways.
Select the start point. 
Select a point through which the arc will pass. 
Select the endpoint. 
Local Menu Options:
These options are available after the fist point of the arc is placed:
- Center: Before you click the arc start point, you can select Center to define the center point first.You can then click the center point and start point.
- Angle: Rather than clicking the end point, you can select the Angle or Chord Length local option.
- End: With this option, after you click the arc start point, you can select End to click the end point.
- Radius: Then you can click the center point, or use the Angle, Direction, or Radius local option.
- Angle: Rather than clicking the end point, you can select the Angle or Chord Length local option.