You are describing a rectangle NOT a square!
The length of the diagonal of a square whose side lengths are 7 square root 2 (9.89949494) is: 14 units.
45
A Square
They are tiles whose length is the same as their breadth.
100 cm
7 inches
15 units of measurement
The length of a rectangle whose area is 72 square meters and whose width is 6 meters, would be 12. Note that 12 x 6 = 72.
Since the lengths on both sides of the square are the same the side length will be 6cm.
area - width = length
It could be a square whose sides are sqrt(1/3) of the original square or a rectangle whose length is the same as the side of the square but whose width is one third of that. There are many other possibilities.
It is the area covered by a square whose sides are 1 metre in length.