Use Polar Tracking and PolarSnap
 
 
 

To draw objects using polar tracking

  1. Turn on polar tracking and start a drawing command, such as ARC, CIRCLE, or LINE.

    You can also use polar tracking with editing commands, such as COPY and MOVE.

  2. As you move your cursor to specify points, notice the dotted polar tracking line that appears at the tracking angles you specified. Points you specify while the line is displayed conform to the polar tracking angle.
 Command entry: DSETTINGS