King Size Detective What Size Is A King Size Duvet Cover Set And Will It Fit 2 Single Beds Joined?

What size is a king size duvet cover set and will it fit 2 single beds joined? - king size detective

I have decided 2 beds in my room and to sit down together and now I need to fit a duvet cover, so I thought that might fit a king, but somebody meters, "he said, did not fall. So help me !!!!:( pleaseeeeeeeee