Killer

Q: There is a round house on the hill, in the house a mother and father and daughter live there. The mother and Father go out for a party, they come back the daughter is dead. They ask the butler,cook, and maid who killed the daughter. The maid said i was cleaning corners and the butler says i was helping make dinner. The cook says i was making dinner. Now who killed the daughter?

A: The maid because they live on a round hill and you can't clean corners.