Radar/Stealth question

This is just something I was wondering to myself the other day..

Radar reflects of flat surfaces, and so stealth aircraft have angled surfaces to scatter the radar signal, correct?

Well what about the dorsal and ventral sides of the aircraft? Even stealth aircraft are comparatively flat for areas such as their wings, so could a satellite based, downwards looking radar be used to locate conventional stealth aircraft?

:confused: