Compare ONO bond angle in nitrogen oxides Which has maximum $\ce{ONO}$ angle?
  
  
  $\ce{NO3-}$  
  $\ce{NO2+}$
  $\ce{NO2-}$
  $\ce{NO2}$
  


According to me $\ce{NO2+}$ should have the maximum angle because the structure is linear but in answer it is given $\ce{NO3-}$. We can consider the lone pair in $\ce{NO2+}$ but still also by VSEPR theory I don't think it is possible to decrease angle from 180 to less than 120.
You are right, that's $\mathrm{NO_2^+}$, since it is linear, and whoever says otherwise is wrong.

Also, those (except for NO2) are not compounds, but particles.