Surface area is the measuring of total area around the shape. The process is just counting all of the squares around the shape.

The formula:

The formula for surface area is the top and bottom are the same so you multiply it by 2 and then you multiply the sides by 4. That will give you your answer. Also you can count the squares and then multiply. A long way of getting it is to count all of the squares one by one. All of this is for a three dimensional object.

The formula for a square is BxH This will always work and get you the answer.

The next thing is removing squares from a 3d object:

When you remove one corner cube the surface area stays the exact same because you still see the same amount of squares when looking from the sides. But when you take away a cube in the middle the surface area actually increases by one. So its pretty cool the way how that works. So sometime when you take it away it stays the same or decreases but when you take one away from inside the middle then it increases.