the square of a number is a number times itself.

To have found the square footage (area) of the structure – you took one side of the square, the linear measurement(distance of a straight line) measurement from one corner times the linear measurement of the other side from the same corner and multiplied them.

The square root of this area measurement will give you the total linear measurement of those two sides. You then multiply that square root by TWO to get the perimeter linear measurement of footprint of the square/rectangle structure.

If you have indentations, protrusions (like alcoves, entries, cantillevers, or an ell shape, something other than a square or rectangle you’d have to say so.

Now, if your structure is a roundish shape other than a square or rectange (like an octagon or circle, or whatever) you’d have to say so also.

I really dislike ambiguous questions.