What atomic or hybrid orbitals make up the sigma bond between c1 and c2 in tetrafluoroethylene, c2f4?

The atomic or hybrid orbitals that make up the sigma bond between C1 and C2 in tetrafluoroethylene, C2F4 are the sp2 hybrid orbitals. Tetrafluoroethylene C 2F4 has double bond between C1 and C2. So, sigma bond is made sp2hybrid orbitals.

To add, the simplest perfluorinated alkene, Tetrafluoroethylene belongs to the family of fluorocarbons.