Ai, Bi and Ci are fuzzy subsets defined by the corresponding membership functionsand fi(u) is a crisp function. In the present work, using MATLAB tool box three fuzzysubsets are assigned to the three inputs, as shown in Figure 4-6. The relationshipbetween input and output variables is developed through fuzzy rules. In total 27 rule sare shown in Figure 7. Gaussian membership function is chosen for input variablewhich gives less error when compare with the other membership functions.