GEOMETRY/DRAWING
Create Circles 
Surface : Geometry -> Create -> Object -> Circle -> Enter Center
-> 0,
0 -> Normal to Z -> Radius -> 10, 6 and 5 respectively
Then Geometry -> Delete -> Surfaces
Create Electrode Surface
Geometry -> Edit -> Divide -> Num Divisions -> Select three circle
lines -> Number of Division -> 4
Create Center Portion Area
Geometry -> Create -> Lines -> Enter Point-> 2,0 -> 0,2 -> -2,0 ->
0,-2 -> 2,0 -> Joint -> Escape
Segment the Surfaces
Geometry -> Create -> Lines -> Choose the Points
-> Finally you obtain the 4-sided rectangles for all areas