Create a fillet wherever you want two raster lines to meet at a rounded or square corner.
You can specify a radius for the corner arc by drawing a line or entering a numeric value. This radius is used as the default value for the next use of the fillet command in this editing session. If you specify no radius value, the two lines are extended to intersect.
If you want to leave a small gap between the fillet and one of the lines, set the Trim option to No Trim.