Enigma 1221: Flower beds
From New Scientist #2377, 11th January 2003 [link]
Some time ago (Enigma 1112) George constructed a patio divided into seven rectangular zones of different shapes. He is now planning to divide his large square garden into seven rectangular flower beds. The beds are all different shapes, but all have the same area and cover the whole area of the garden with no gaps.
The width of the rose bed is exactly 25 feet. The side of the square garden is also a whole number of feet.
How many feet?