Rounding in a Drawing
Add a rounding to a corner formed by two straight lines, between two arcs, or between a line and and arc. You can select additional properties from the additional menu or define rounding properties in the dialog box.
- Select Drawing | Line Tools | 
 Round. - Click two lines which intersect each other.
 - Select the additional rounding properties. 
 Additional Rounding Properties - Select the lines as follows:
- Select two straight lines.
 - Select two arcs.
 - Select a line and an arc.
 
 - Define the rounding data in a dialog box. 
 Rounding Data - Select OK.
 
Example:

Note: 
  - You can edit the rounding radius by selecting the Edit Round function.
 - If the 2D Constraint Manager is enabled, the rounding involves a radius dimension, coincident constraints and tangent constraints.
 - You can also edit the rounding using a dimension constraint. Note that this change will affect the radius dimension but not the lines between which the rounding was originally added.
 
