This is the one that specifically discusses telescope array (but your formula is still correct) https://en.wikipedia.org/wiki/Angular_resolution#Telescope_a...

60GHz has a wavelength of 5mm. Effective diameter would be ~13000km. Someone check my math but I end up with 5e-3/13e6 radians or ~.0001 arcseconds. Hubble is ~.05 arcseconds.