How do you calculate 720 square feet into linear feet?

Answer 1

You don't. There's not enough information. Square feet measures area. Linear feet measures length. It's possible to break an area down to two lengths, such as a square with area 4 could be broken down to 2x2 by taking its square root. 2 length and 2 width. But if it's not a square and you don't already know one of the sides (which this doesn't give) then there's no way to do it.

If the shape you're asking about is a square then it would be 26.83 feet on each side. 26.83x26.83 (approximately).