*Tools -> Edit geometry -> geometry functions -> centroid of A
*Tools -> Edit geometry -> geometry functions -> interior points 
*Tools -> Generalization -> JTS
*PlugIns -> Map Generalisation -> Not scale def. alg. -> Lines -> JTS
*Tools -> Edit Geometry -> Convert -> Planar graph
*Tools -> QA -> Validate Selected layers
*Tools -> Edit Attributes -> Transfer Attributes
*Tools -> QA -> Layer statistics
[Right Click] -> Explode Selected features
*PlugIns -> MG -> Scale DA -> Lines -> Displace lines plugin