안녕하십니까? vs 안녕하십니다
So it seems that when you greet someone in the formal tone you're supposed to greet them with 안녕하십니까?. This seems kind of weird to me though to greet someone with a question because doesn't 안녕하십니까? essentially mean "Hello?"? Could you ever greet someone with 안녕하십니다 or do you always have to greet someone with 안녕하십니까? ?

Question

Answer

안녕하십니까? is more like How are you? 
if you look up the dictionary, you'll see 안녕하다 means 'being well.' 
Although you put a question mark at the end when you write it down, we don't necessarily raise the pitch at the end. 
And 안녕하십니다 doesn't make sense.