John Gill Commentary Exodus 26:2

"The length of each curtain shall be eight and twenty cubits, and the breadth of each curtain four cubits: all the curtains shall have one measure." — Exodus 26:2 (ASV)

The length of one curtain shall be twenty eight cubits
Or fourteen yards:

and the breadth of one curtain four cubits ;
or two yards; according to the common notion of a cubit being half a yard; but if, as Dr. Cumberland says, the Jewish and Egyptian cubit was three inches longer, this will make a considerable difference in the length and breadth of those curtains, especially in the former:

and everyone of the curtains shall have one measure ;
be of equal length and breadth.