So we will take 891 blocks, and divide it into 45, 19.8 Since it is not a full block, and we cannot use non-full blocks, We will round up.(Which is 20 blocks) So with a Centered mass of around 20. We need 891 Total blocks of location to build this. Now take your 1,620 blocks and divide it by 2 That means We know we need 810 blocks for the backwalls,and now what is 36 +45, Thats 891. Which is effective to lead up to 1,620 Total blocks (Counting walls) So i want to build a tower 45 blocks high, and 36 blocks wide. So if you want it to be 45 blocks high, Build a temporary wall to 45 blocks, (Make sure to increase it by atleast 5 blocks if you plan to add a roof)
If you wish to build a tower like this, Make sure you have 36 blocks Flattened out, AND Make sure how high you want it to go