This paper presents two general methods to handle uncertainties in the right hand side parameters of a linear programming (LP) model by means of interval type-2 fuzzy sets (IT2 FS). In this paper, a LP problem with uncertain right side parameters treated as interval type-2 fuzzy sets is solved by two optimization strategies: The first one is a type-reduction method and the second one is a pre-defuzzified ¿ - cut approach. After the IT2 FS inference process, a real-valued solution must be found. In this way two methods based on classical optimization routines are presented to obtain optimal solutions when uncertain right hand side parameters exist.