my dog ate some hair off the floor 😒?

How much hair? Most likely the dog will be okay. Canines are very resilient! And dogs are known for eating all kinds of stuff they shouldn't. But... I guess if you had long hair, got shaved bald, and he ate it _all_, that could be a real problem. That sounds silly, but people do crazy things. I would say keep an eye on him for the next several days, give him plenty of water and watch for changes in behavior, like not wanting to eat, throwing up, pain in his abdomen, stuff like that. It would be a good idea to call a vet if you're concerned-- they can provide much more experienced advice, and they'll be happy to help.

It's fine

If it was short hair, no problem. Long hair CAN pose difficulties in the intestines, though.

yep