Which of the following molecules are planar?

${\mathrm{XeCl}}_2$,${\mathrm{XeBr}}_2$and ${\mathrm{XeCl}}_4$has  planar structure.

One xenon atom and two chlorine atoms make up xenon dichloride$XeC{l}_2$. The xenon atom, which contains two chlorine atoms bonded to it, is surrounded by two single bonds in the lewis structure of $XeC{l}_2$, and each chlorine atom has three lone pairs.