Impossible, It would almost completely depends on the size of the pieces, which you don’t have. Imagine this is a rectangle. You could have two large pieces on each side, making a total of 8 pieces around the perimeter. Then the remaining 100 pieces would be much smaller in the center of the puzzle. You could reduce it to 4 pieces around the side, or increase to 16 pieces around the side. My principle is still correct. There is not enough information in the question to be able to make an educated estimate.