Originally Posted by Greenheron
Shouldn't the each side of the diamond be the same measurement as one segment of the hexagon?
Yes they should be the same size as the side of a hexi. If you are piecing with templates like EPP, you can lay out your hexi templates in the pattern that you want, leaving exactly enough space for the diamond path. That will be the size of your diamond template.
Clear as mud? I can take a few pics and post if you like.