i am not sure what the cpd is exaclty     (+)-Cis-Co₂Cl₂

so      Cl             Cl        
            \           /
              Co--Co

this is what I am seeing with the Cis-isomer.  To be tetrahedral, Co would need two lone pairs of electrons.  Which I believe it does.  So it would look something like below. where  :  and ..  are lone pairs.

          Cl            Cl        
            \          /
          : --Co--Co-- :
             /          \
            ..           ..

The tetrahedral is formed between the Two Co's and one Cl and two lone pairs  like this:

                        Cl        
                       /
               Co--Co-- :    with all angles  120 degrees.
                        \
                         ..


The (+) if at the beginning of the name means it rotates ( I think + is clockwise) in polarized light.

I hope i did this right, cause I'm not sure about the cpd.  But you can also use HyperChem on the computers to find symmetry or structure.  I am not at home so I can't use HyperChem right now.

Hope this helps...and hope its right.

The complex is octahedral like all those of trivalent cobalt, not tetrahedral. Octahedral complexes are chiral (have optical isomers) if they contain three chelate rings as in [Co(oxalate)3]3-; or if there are two rings and the remaining groups are cis, as in cis [Co(ethylenediamine)2Cl2]+. If you build models this will become clear. Trans [Co(ethylenediamine)2Cl2]+ has both chelate rings in the same plane, therefore has a plane of symmetry and is not chiral.

so is Cis-[Co(ethylenediamine)2Cl2]+   the actual cpd.....boy it really helps to know what it is I was going to try and explain .