BEG+END allows you to specify an arc's start point,
endpoint, and the included angle.

Enter the included angle of the arc. This represents the
angular portion of the arc (in degrees) that lies between
the two points to be selected. Press <Enter> to accept 
the default angle value in parentheses on the Prompt Line.

Next, indicate the start point and endpoint for the arc,
using an option from the Position Menu.

The start point and endpoint are projected to the current
construction plane, and the arc is created in the current
construction plane.
