A square is inscribed inside a circle, as illustrated above. The radius of the circle is units. If all of the square's diagonals pass through the circle's center, what is the area of the square?

When the side of a certain square is increased by 2 inches, the area of the resulting square is 64 sq. inches greater than the original square. What is the length of the side of the original square, in inches?

If the area of a square is 25 inches squared, what is the perimeter?

The area of square R is 12 times the area of square T. If the area of square R is 48, what is the length of one side of square T?