Use the ‘Scissors Tool (C)’ to select the path. Next use the Object > Paths > Separate menu item to separate the pat into segments. Delete the segment that you want to replace. Use the ‘Line Tool (L)’ to draw the straight line across the gap. When doing this you probably want to have ‘Snap to Points’ enabled on the Layout menu.
I’m not sure why this only works if one has used the scissors to perform the selection, but that has been my experience with v3.5.4
Use the ‘Scissors Tool (C)’ to select the path. Next use the Object> Paths> Separate menu item to separate the pat into segments. Delete the segment that you want to replace. Use the ‘Line Tool (L)’ to draw the straight line across the gap. When doing this you probably want to have ‘Snap to Points’ enabled on the Layout menu.
I’m not sure why this only works if one has used the scissors to perform the selection, but that has been my experience with v3.5.4