A Linear Ring <math>R</math> is '''planar''', if it is a valid Linear Ring and the distance of all points to any plane <math>E_{ijk}</math>, that is defined by three co-linear points <math>P_i</math>, <math>P_j</math> and <math>P_k</math> aufgespannt werden, is less than a given threshold <math>\epsilon</math> :
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A Linear Ring <math>R</math> is '''planar''', if it is a valid Linear Ring and the distance of all points to any plane <math>E_{ijk}</math>, that is defined by three co-linear points <math>P_i</math>, <math>P_j</math> and <math>P_k</math>, is less than a given threshold <math>\epsilon</math> :