Catalog of Radio Galaxies with z>0.3. III: Angular Sizes and Flux Density According to the NVSS Data

We describe the procedure of the construction of a sample of distant ($z>0.3$) radio galaxies using the NED, CATS and SDSS databases for further use in various statistical tests. We believe the sample to be free of objects with quasar properties. This paper is the third part of the description of the radio galaxies catalog that we plan to use for cosmological tests. We report the results of the sample of angular sizes for the NVSS survey list objects, and its preliminary statistical analysis. Three-parameter diagrams "angular size-redshift-flux density" and "angular size-redshift-spectral index", and their two-parameter projections are constructed. Three subsamples of radio galaxies are separated in the "source size--flux density" diagram.