TODAY IS THE DAY!!!!!! Pillow form is 14" square. Pillow front (embroidered is 15x15) Directions for pillow form with 19" square front for 18" pillow form calls for two back pieces (cuts) of 19x15.
Next step, the question is, the reduction of the 19x15 pieces to 15x(?).
So, what percentage of 19 is 15? (divide 15 by 19) 79% (actually78.947368...)
Now, 79% of 15 is 11.85 (about 11 7/8")
Many of you came close...Don't feel bad if you factored in other pieces. In teaching, those are what are called distractors. The information given is accurate, but is unnecessary. That's why math problem solving is so difficult. As the kids say TMI.
Hope you had some fun following this.