Putting all those tiles down one at a time can take forever, but there is a quicker way.

Once you have a line of tiles, make a copy of the piece, rotate it 90 deg. and just use the clone tool to copy the line of tiles back onto the original making another side of the square, then rotate again and make the next side. This works as long as the piece is symetrical and does not have directional shadows on it. Here is a screen shot of me part way through, and the finished tile.

Click image for larger version. 

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