Abstract
In the theory of hypergeometric and generalized hypergeometric series, classical summation theorems have been found interesting applications in obtaining various series identities for pi, pi(2) and 1/pi. The aim of this research paper is to provide twelve general formulas for 1/pi. On specializing the parameters, a large number of very interesting series identities for 1/pi not previously appeared in the literature have been obtained. Also, several other results for multiples of pi, pi(2), 1/pi(2), 1/pi(3) and 1/root pi have been obtained. The results are established with the help of the extensions of classical Gauss's summation theorem available in the literature.