It might be 275?
That’s the answer I got.
Here’s what I did:
I used the formula A = bh + 2ls + lb
B being the base, h being the height and L being the length.
I substituted the numbers in, giving me this new formula:
a = 11 x 13 + 2 x 11 x 4 + 11 x 4
which gave me 275.
Hope this helps!