Given: The side of the square park = 60 m
The length of the rectangular park = 90 m
According to the question,
Area of square park = Area of rectangular park
⇒ side x side = length x breadth
⇒ 60 x 60 = 90 x breadth
⇒ breadth = (60 x 60)/90 = 40 m
Thus, the breadth of the rectangular park is 40 m.