The answer is 5 pieces. To get this answer lets first change 8 1/2 to 8.5 so we can divide. Now we are going to divide the 36 feet by the 8.5 pieces he needs cut. That answer is 4.24. So he will have 4 pieces of the 8 1/2 sizes he needs and have 1 leftover piece of about 2 feet long or so. So that equals 5 pieces.