May 2017 Puzzle

When frosting a 9-inch by 12-inch rectangular cake using red, white, and blue frosting, Emily accidentally applied the frosting incorrectly.  The frosting was supposed to be applied in 3-inch by 12-inch strips as shown in Figure 2 below. However, she applied it in 4-inch by 9-inch strips as shown in Figure 1.  Being the clever person that she is, Emily figured out a way to cut the cake into four pieces in order to reassemble them in the desired form.  How did she do it? 

grid of 4 by 12 squares vertically in red, then in white, then in bluegrid of 3 by 12 squares in horizontally red, then in white, then in blue

**May Solutions are Due by May 19**