Draw all the isomers (geometrical and optical) of:
$(i)$ $[CoCl_2(en)_2]^+$
$(ii)$ $[Co(NH_3)Cl(en)_2]^{2+}$
$(iii)$ $[Co(NH_3)_2Cl_2(en)]^+$

(N/A) $(i)$ $[CoCl_2(en)_2]^+$: This complex exhibits geometrical isomerism (cis and trans). The cis-isomer is optically active (exists as a pair of enantiomers),while the trans-isomer is optically inactive (achiral). Total isomers = $3$ (cis-d,cis-l,trans).
$(ii)$ $[Co(NH_3)Cl(en)_2]^{2+}$: This complex exhibits geometrical isomerism (cis and trans). The trans-isomer is optically inactive. The cis-isomer is optically active and exists as a pair of enantiomers. Total isomers = $3$ (cis-d,cis-l,trans).
$(iii)$ $[Co(NH_3)_2Cl_2(en)]^+$: This complex exhibits geometrical isomerism. There are $5$ possible isomers: trans-trans,cis-trans,trans-cis,and two optically active cis-cis isomers (d and l).