d3.js - How to work with (custom) Topojson's Arc? -

i have 2 questions regarding topojson's arcs. i'm working on world map not uses countries regions. world map works fine, regions causes headaches. :)

question 1: there documentation borders/arcs on map? eg, path arc id 296 values [[5674,8510],[4,34],[-11,-7],[-17,20],[-3,33],[35,16],[35,9],[31,-10],[28,2]]? can’t find easy-to-read overview of used arcs.

question 2: want divide countries in sections: west, east, northeast, southwest etc… eg if have:

{         "type":"multipolygon",         "arcs":[            [                  [294, 295]            ],            [                  [29 ]            ]         ],        "id":"united kingdom" } 

do have create new arcs? , what’s easiest way that?