<p><span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">statistic indexes have been used to assess the accuracy of the results. The results of the examinations indicate that using MLP model along with simultaneous use of dimensionless parameters for the purposes of estimating discharge coefficient: the ratio of water behind the weir to the channel width (h/b), ratio of weir crest length to weir height (L/W), relative Froude number (F=V/&radic;(²Side weirs are used in open channels to control flood and the flow passing through it. Discharge capacity is one of the crucial hydraulic parameters of side weirs. The aim of this study is to determine the effect of the intended dimensionless parameters on predicting the discharge coefficient of triangular labyrinth side weir. MAPE, RMSE, and R</span></span><span style="font-family:Arial,Helvetica,sans-serif"><span style="font-size:14px">gy</span></span><span style="font-size:14px"><span style="font-family:Arial,Helvetica,sans-serif">)) and vertex angle (Ï´), offered the best results (MAPE= 0.67, R²= 0.99, RMSE = 0.009)&nbsp; in comparison with other models.</span></span></p>