I believe the word "panel" is misued. I suspect it is repeats and not panel. Repeats are usually 22"-24" and you will need the number of repeats the fractured cut requires. If there are 6 cuts then you will need 6 repeats. Get a clarification of the terms and buy accordingly.
And remember the "repeat" is only accurate down the side of the fabric. The same repeat on the other side may not be in the same registration as that down the length of the fabric.
This can be misleading as they may look the same. the other side can be used for another set of blocks.