This is one of those handy tips can save a lot of time to newcomers.
Instead of the tedious job of exploding your polyline to fillet with arcs, follow the below steps:
- select the polyline
- pick a corner node (not along a section of line)
- left-click on one of the corner nodes and keep the left button down until the pet palette appears
- choose the 'Fillet...' button (should be the second button from the left in the upper row of buttons)
- then set the options in the pet palette as you like
- and click on 'OK'.
Of course you can disable the "apply to all corners" option and set the radius for each junction. You can also choose to Chamfer the corner(s) instead of Filleting them.
Hint: The next node you pick will have the fillet option ready to go in the pet palette.
The original thread can be found here.