Tahereh Houlari - MA degree, School of Mathematics and Computer Sciences , Damghan University , Iran,
Adabitabar Firozja - Academic member, Department of mathematics , Qaemshar Branch , Islamic Azad University , Qaemshahr , Iran

In this paper , initially we define piecewise linear approximation of a fuzzy numbers by (m,n)-knot left right fuzzy numbers . Fuzzy c-means (FCMs) is an important and popular unsupervised partitioning algorithm used in several application domains such as pattern recognition , machine learning and data mining . For approximate of fuzzy numbers with (m,n)-knot left right piecewise linear fuzzy numbers , we used of FCMs method to approximate piecewise linear left and right functions of fuzzy numbers . At the end of this paper numerical examples are given.

Fuzzy numbers , Approximation , fuzzy clustering method