so, if you are trying to make this block fit into the swap rules you need to measure it- then see if the measurements are divisible by 3---meaning if it is (9 1/2" x 12 1/2" ---with the 1/2" seam allowance it would be a correct size---
you have to start with measuring your block- subtract 1/2" from the measurment- if the number left can be divided by 3 you add the 1/2" seam allowance back on and are 'good to go'
if it is not divisible by 3 you would need to either trim it down to make it work- or add to it---such as- if it measures 8 1/2" x 12 1/2"...you would need to add an inch to the 8" side-
if it measured 13"x 16" you would need to trim away a 1/2" (making it 12 1/2" x 15 1/2"- which divides by 3)