The shape function model is used to calculate the coupling constant in perturbation theory and also the non- perturbative free parameter concerned with the QCD theory. This analysis is based on employing the event shape observables 〈B_T 〉 ,〈B_W 〉 ,〈1-T〉,〈ρ〉. By fitting the Monte Carlo data as well as the AMY data with the shape function distribution, we find combining the results of all variables. We have obtained the mean value of the strong coupling constant a_s (M_(Z^0 ) )=0.11596±0.00778 and the nonperturbative parameters λ_1=1.0779±0.02276GeV. Our results are consistent with the values obtained from other experiments at different energies and QCD predictions. We explain all these features in this article.

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