You have a birthday cake and have exactly 3 slices to cut it into 8 equal pieces. How do you do it?
Cut in half, stack, cut in half, stack, cut in half. All you have to worry about is the 45 degree rotation of one of the 4 pieces after the second cut. Blade can be kept in place, like a paper cutter, as to minimize the margin for error.
Slice it horizontally across the middle creating two equal halves top and bottom. Then simple two slice cross from above like normal.
Cut each slice into 3 slices. Then eat one of them.
Nov 21, 2010