Area of rectangle =(19×17) m2=323 m2 . Since, area of square = area of rectangle, therefore,
Area of the square =323 m2.
If the side of the square is a, the area = a2.
⇒ a2=323 m2.
Since 323 is very close to 182 (i.e 324).
Hence, a ≈ 18 m.