Solar global irradiation using the Angstrom linear model is widely discussed in the literature. Most of these studies discuss the linear relationship between sunshine duration and global solar irradiation, which is a rigged concept and cannot provide information about the annual variations. This study presents the variation of global solar irradiation through solar irradiation polygon (SIP), which reflects the monthly and seasonal variation of solar irradiation throughout the year. The variation of solar radiation is referred to the state of the atmosphere in the lower layer that is affected by the synoptic weather situation. The model parameters a(s) and b(s) are calculated month to month throughout the year for seven stations in Jordan. On the other hand, the classical model parameters are calculated for the whole year for the same stations.