Question

there is a square park in our locality. the area of the rectangular park is 78 sqm. less than twice of the area of that square-shaped park whose length is 5m. more than the length of the side of that park and the breadth is 3m. less than the length of the side of that park. Let us write by calculating the length of the side of the square-shaped park.​

Answer 1

Here, Length of Rectangular Park =l

Breadth of Rectangular Park =l−3

Altitude of Triangular Park =12

Breadth of Triangular Park =l−3

Now, 

ARectangle=l(l−3)

ATriangle=21×12(l−3)

ARectangle−ATriangle=4

⇒l(l−3)−21×12(l−3)=4

⇒l2−9l+14=0

⇒(l−2)(l−7)=0⇒l=2,7

Since, breadth is l−3 , l=2 

∴l=7 m  and  breadth =7−3=4 m

I HOPE it's HELPFUL for you