Which is/are in linear shape?

Although $N{O}_2$ is a bent molecule, when you remove an electron from it, creating it ${\mathrm{NO}}_2^{+}$, the molecule becomes linear due to the loss of a lone electron. The two O atoms and the single electron on the center atom in ${\mathrm{NO}}_2^{+}$ are not in repulsion with one another.

With five pairs of electrons around Xe in ${\mathrm{XeF}}_2$, the structure is trigonal bipyramidal. The three lone pairs are located at the equator, whereas the fluorine atoms are in linear places. A linear molecule is ${\mathrm{XeF}}_2$.

The molecular geometry of ${\mathrm{I}}_3^{-}$- is linear. Despite having three iodine atoms, one of them has a negative charge, which results in three lone pairs of electrons and two bond pairs.

Hence ${\mathrm{NO}}_2^{+}$ ,${\mathrm{XeF}}_2$and ${\mathrm{I}}_3^{-}$are in linear shape