To finish our last row, we should make 1 dc into the same space where we made our first chain of 3 (picture 31) We are not going to do slip stitch. Instead, we're going to make an invisible join.
Cut the yarn and pull it through the stitch. Thread a needle. Skip the beginning chain 3, and insert the needle under both loops (front & back) of the next stitch from back to front, as it is shown in the picture 32, and pull it through