Cosmological models and the value of their parameters are at the center of the debate because of the tension between the results obtained by the SNe Ia data and the Plank ones of the Cosmic Microwave Background Radiation. Thus, adding cosmological probes observed at high redshifts, such as Gamma-Ray Bursts (GRBs), is needed. Using GRB correlations between luminosities and a cosmological independent variable is challenging because GRB luminosities vary widely. We corrected a tight correlation between the rest-frame end time of the X-ray plateau, its corresponding X-ray luminosity, and the peak prompt luminosity: the so-called fundamental plane relation, using the jet opening angle. Its intrinsic scatter is 0:017 m 0:010 dex, 95% smaller than the isotropic fundamental plane relation, the smallest compared to any current GRB correlation in the literature. This shows that GRBs can be used as reliable cosmological tools. We use this GRB corrected correlation for the so-called platinum sample (a well-defined set with relatively flat plateaus), together with SNe Ia data, to constrain different cosmological parameters like the matter content of the universe today, M, the Hubble constant H0, and the dark energy parameter w for a wCDM model. We confirm the wCDM model but using GRBs up to z = 5, a redshift range much larger than one of SNe Ia.