Let the length of the rectangular park be x m then, breadth be (x−3) m
∴ Area of rectangular park = x(x−3) m2
Area of isosceles triangular park = 12 (x−3)×12 m2
= 6(x−3) m2
According to the given condition,
x(x−3)−6(x−3)=4
x2−3x−6x+18=4
x2−9x+14=0
x2−7x−2x+14=0
x(x−7)−2(x−7)=0
(x−2)(x−7)=0
x=2 or 7
∴ x=7 m
(As breadth can't be negative)
and x−3=(7−3) m=4 m
Hence, length and breadth of the rectangular park is 7m and 4m respectively.