Cutting Equally

Given a rectangular cake within which a rectangular piece removed (any size or Orientation). How would you cut the remainder of the cake into two equal halves with one straight cut of a knife?

Answer:

If you cut a rectangular thing along the center (horizontally, vertically or at any angle), you will get two halves. Using this idea, find the centers of both - the original cake and the removed piece. Now, cut the reminder along the line connecting these two centers. This is true because this line cut both - the original cake and the removed piece - in half, thus the remainder into two halves too.