To Insert an Edge by Deflection Angle

Select the Insert Deflection Line tool.
A line beginning with LOC DEF appears in the Command list box below the active (highlighted) line.

The dialog changes to provide input fields for the tool. The Angle and Length values from the last Insert Deflection Line command appear on the command line.
Select the Angle field to key in the deflection angle.
Select the Length field to key in the length of the edge.
Turn on Back Sight if the edge is a back sight edge. The default is forward sight.
Click on the direction of the curve, Left or Right arrow.
L (left) or R (right) appear in the command line.