First of all, their measurements will be different from ours. I didn't see the pattern on Google:
https://www.google.com/search?q=six+...topper&imgrc=_
There are probably going to be in Y set in seams. You might see if you can find an easier pattern on Google. I made these last years out of charm squares:
http://quilti.com/christmas-table-to...andy-quilting/
You might also check out this Google search:
https://www.google.com/search?q=char...acAWMQ_AUIOygB
The only other option is to draw out the pattern to scale and add 1/4" seams. Good Luck.