Farmer's Treasure was designed by Sarah & Susan of Farmer's Daughters Quilts, and is 73" x 94".  
 
Have you tried the Bloc Loc rulers? I use them in almost every quilt I make, and just love them.  For these blocks, Sarah & Susan used the 3 1/2" Half Square Triangle - any size from 3 1/2" - 6 1/2" will work.  These are NOT required, just recommended, because they are so helpful!