Not sure if this is the best way to do it but on your widget you are trying to hide/show, for the "Visible" script, you can do something like this:
"[[radio_button_widget_variable]]" == "value"
So if you had a radio button named rd_yes_no, and set your radio button to a list ["yes","no"] then it would look like this:
"[[rd_yes_no]]" == "yes"