The shape of a molecule or ion can be determined using VSEPR theory and hybridization:

1. $\text{NO}_2^-$: The central nitrogen atom is $sp^2$ hybridized and possesses one lone pair of electrons, resulting in a bent or V-shape.
2. $\text{SO}_2$: The central sulphur atom is $sp^2$ hybridized and has one lone pair of electrons, giving it a bent shape.
3. $\text{NO}_2^+$: The central nitrogen atom is bonded to two oxygen atoms via double bonds and has zero lone pairs. It undergoes $sp$ hybridization, resulting in a perfectly linear shape with a bond angle of $180^\circ$.
4. $\text{O}_3$: The central oxygen atom in ozone is $sp^2$ hybridized and contains one lone pair, which also leads to a bent shape.