The front length is 49 inches The back length is 53 inches 53 - 49 = 8 Then the 8 divided by 2 = 4 So I added the 4 inches to the front length 45 inches to give me 49 inches for the side length Or minus 4 from 53 to give 49inches In essence, the side length will just be the mid number between the front measurement and back measurement 49 is the mid number between 45 and 53 if you count it. I hope this is understandable to you, wish I can explain better
