How many valence electrons occupy sigma and pi bond orbitals in anthracene?

There is no more than 1 sigma bond between any two atoms. Molecules with rings have supplementary sigma bonds, such as benzene rings, which have 6 C-C sigma bonds within the ring for 6 carbon atoms. The anthracene molecular formula is C14H10, it has three rings so that the rule contributes the number of sigma bonds as 24 added with 3 is 27, which will be subtracted with 1 which will give 26.