Let the ratio be x m.
Length of Park = 3x m
and Breadth of Park = 5x m
Perimeter of Rectangular Park = 450m
Perimeter of Rectangle = 2*(l+b)
Length of Park = 3x m = 3*28.125 m = 84.375 m
Breadth of Park = 5x m = 5*28.125 m = 140.625 m
Area of Rectangle = l*b
Area = (84.375*140.625) m²
Area of Park = 11865.23 m²
HOPING THAT IT WILL HELP YOU!!!